5-(heterocyclic alkyl)-6-aryl-dihydropyrimidines

ABSTRACT

This invention is directed to the use of dihydropyrimidine compounds, which are selective antagonists for cloned human α 1C  receptors, for the treatment of benign prostatic hyperplasia and other diseases where antagonism of the human α 1C  receptor is useful. The invention further provides a pharmaceutical composition comprising a therapeutically effective amount of the above-identified compounds and a pharmaceutically acceptable carrier.

This application is a divisional of U.S. Ser. No. 08/978,682, filed Nov. 26, 1997, now U.S. Pat. No. 5,942,517, issued Aug. 24, 1999 which is a continuation of U.S. Ser. No. 08/340,611, filed Nov. 16, 1994, now abandoned.

BACKGROUND OF THE INVENTION

Throughout this application, various references are referred to within parentheses. Disclosures of these publications in their entireties are hereby incorporated by reference into this application to more fully describe the state of the art to which this invention pertains.

Benign Prostatic Hyperplasia (BPH), also called Benigr. Prostatic Hypertrophy, is a progressive condition which is characterized by a nodular enlargement of prostatic tissue resulting in obstruction of the urethra. This results in increased frequency of urination, nocturia, a poor urine stream and hesitancy or delay in starting the urine flow. Chronic consequences of BPH can include hypertrophy of bladder smooth muscle, a decompensated bladder and an increased incidence of urinary tract infection. The specific biochemical, histological and pharmacological properties of the prostate adenoma leading to the bladder outlet obstruction are not yet known. However, the development of BPH is considered to be an inescapable phenomenon for the aging male population. BPH is observed in approximately 70% of males over the age of 70. Currently, in the United States, the method of choice for treating BPH is surgery (Lepor, H., Urol. Clinics North Amer., 17, 651 (1990)). Over 400,000 prostatectomies are performed annually (data from 1986). A medicinal alternative to surgery is clearly very desirable. The limitations of surgery for treating BPH include the morbidity rate of an operative procedure in elderly men, persistence or recurrence of obstructive and irritative symptoms, as well as the significant cost of surgery.

α-Adrenergic receptors (McGrath, et. al. Med. Res. Rev., 9, 407-533, 1989) are specific neuroreceptor proteins located in the peripheral and central nervous systems on tissues and organs throughout the body. These receptors are important switches for controlling many physiological functions and, thus, represent important targets for drug development. In fact, many α-adrenergic drugs have been developed over the past 40 years. Examples include clonidine, phenoxybenzamine and prazosin (treatment of hypertension), naphazoline (nasal decongestant), and apraclonidine (treating glaucoma). α-Adrenergic drugs can be broken down into two distinct classes: agonists (clonidine and naphazoline are agonists), which mimic the receptor activation properties of the endogenous neurotransmitter norepinephrlne, and antagonists (phenoxybenzamine and prazosin are antagonists), which act to block the effects of norepinephrine. Many of these drugs are effective but also produce unwanted side effects (for example, clonidine produces dry mouth and sedation in addition to its antihypertensive effects).

During the past 15 years a more precise understanding of α-adrenergic receptors and their drugs has evolved through increased scientific scrutiny. Prior to 1977, only one α-adrenergic receptor was known to exist. Between 1977 and 1988, it was accepted by the scientific community that at least two α-adrenergic receptors—α₂ and α₂—existed in the central and peripheral nervous systems. Since 1988, new techniques in molecular biology have led to the identification of at least six α-adrenergic receptors which exist throughout the central and peripheral nervous systems: α_(1A), α_(1B), α_(1C), α_(2A), α_(2B) and α_(2C) (Bylund, D. B., FASEB J., 6, 832 (1992)). In many cases, it is not known precisely which physiological responses in the body are controlled by each of these receptors. In addition, current α-adrenergic drugs are not selective for any particular α-adrenergic receptor. Many of these drugs produce untoward side effects which may be attributed to their poor α-adrenergic receptor selectivity.

Since the mid 1970's, nonselective α-antagonists have been prescribed to treat BPH. In 1976, M. Caine, et al. (Brit. J. Urol., 48, 255 (1976)), reported that the nonselective α-antagonist phenoxybenzamine was useful in relieving the symptoms of BPH. This drug may produce its effects by interacting with α-receptors located on the prostate. However, this drug also produces significant side effects such as dizziness and asthenia which severely limit its use in treating patients on a chronic basis. More recently, the α-adrenergic antagonists prazosin and terazosin have also been found to be useful for treating BPH. However, these drugs also produce untoward side effects. It has recently been discovered that the α_(1C) receptor is responsible for mediating the contraction of human prostate smooth muscle (Gluchowski, C. et. al., WO 94/10989, 1994; Forray, C. et. al., Mol. Pharmacol. 45, 703, 1994). This discovery indicates that the α_(1C) antagonists may be effective agents for the treatment of BPH with decreased side effects.

This invention is directed to dihydropyrimidine compounds which are selective antagonists for cloned human α_(1C) receptors. This invention is also related to uses of these compounds for lowering intraocular pressure (Zhan, et. al. Ophthalmol. Vis. Sci., 34 Abst. #1133, 928, 1993), inhibiting cholesterol synthesis (D'Eletto and Javitt, J. Cardiovascular Pharmacol., 13 (Suppl. 2) S1-S4, 1989), benign prostatic hyperplasia, impotency (Milne and Wyllie, EP 0 459 666 A2, 1991), sympathetically mediated pain (Campbell, WO 92/14453, 1992), cardiac arrhythmia (Spiers, et. al., J. Cardiovascular Pharmacol., 16, 824-830, 1990) and for the treatment of any disease where antagonism of the α_(1C) receptor may be useful.

SUMMARY OF THE INVENTION

This invention is directed to dihydropyrimidine compounds which are selective antagonists for cloned human α_(1C) receptors. This invention is also related to uses of these compounds for lowering intraocular pressure, inhibiting cholesterol synthesis, the treatment of benign prosmatic hyperplasia, impotency, cardiac arrhythmia and for the treatment of any disease where antagonism of the α_(1C) receptor may be useful. The invention further provides a pharmaceutical composition comprising a therapeutically effective amount of the above-defined compounds and a pharmaceutically acceptable carrier.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to compounds having the structures:

where A is

where each of Y₁, Y₂ and Y₃ is independently H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocylcoalkyl, polyfluorocycloalkyl or cycloalkenyl; —F, —Cl, —Br, —I, —NO₂, —N₃, —CN, —OR₆, —OCOR₆, —COR₆, —CONHR₆, —CON(R₆)₂, —COOR₆, —CF₃ or together constitute a methylenedioxy group;

where X is S, O or NH;

where R₁ is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocylcoalkyl, polyfluorocycloalkyl or cycloalkenyl; —NHR₆, —N(R₆)₂ or —OR₆;

where R₂ is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocylcoalkyl, polyfluorocycloalkyl or cycloalkenyl; C₃-C₁₀ cycloalkyl-C₁-C₁₀-alkyl, cycloalkyl-C₁-C₁₀-monofluoroalkyl or cycloalkyl-C₁-C₁₀-polyfluoroalkyl; —CN, —CH₂XR₆, —CH₂X(CH₂)_(n)NHR₆, —(CH₂)_(n)NHR₆, —CH₂X(CH₂)_(n)N(R₆)₂, —CH₂X(CH₂)_(n)N₃ or —CH₂X(CH₂)_(n)NHCXR₇;

where n is an integer from 0 to 5 and where X is as defined above;

where R₃ is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocylcoalkyl, polyfluorocycloalkyl or cycloalkenyl;

where R₄ is

where each R is independently H; F; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl;

where R₅ is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocylcoalkyl, polyfluorocycloalkyl or cycloalkenyl; phenyl, thiophenyl, pyridyl, pyrrolyl, furanyl, imidazolyl or indolyl; —COOR₆, —COR₆, —CONHR₆, —CN, —OH or —OR₆;

where each m is independently an integer from 0 to 3; where o is an integer from 1 to 3; where each n is independently an integer from 0 to 5;

where each R₆ is independently H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocylcoalkyl, polyfluorocycloalkyl or cycloalkenyl;

where R₇ is phenyl, pyrrolyl, thiophenyl, furanyl, pyrazinyl, pyrrolyl, naphthyl, indolyl, imidazolyl, benzfurazanyl, benzfuranyl or benzymidazolyl; C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl wherein the alkyl, monofluoroalkyl, polyfluoroalkyl, alkenyl or alkynyl is substituted with phenyl, pyridyl, thiophenyl, furanyl, pyrazinyl, pyrrolyl, naphthyl, indolyl, imidazolyl, benzfurazanyl, benzfuranyl or benzymidazolyl;

where each of Y₁, Y₂ and Y₃ is as defined above; where X is as defined above;

where Z is C₂ alkenyl or alkynyl, CH₂, O, CO, CO₂, CONR₆, S, SO, SO₂ or NR₆; and

where each D is independently CH₂, O, S, NR₆, CO or CS; or a pharmaceutically acceptable salt thereof.

In a preferred embodiment, the compound may have the structures:

Where A, X, Z, Y₁, Y₂, Y₃, R, R₁, R₂, R₃, R₅, R₆, R₇, n and m are as defined above.

In preferred embodiments, the compounds may have the structures:

Other embodiments of the invention include compounds having the following structures:

Where A, X, Z, Y₁, Y₂, Y₃, R, R₁, R₂, R₃, R₅, R₆, R₇, n and m are as defined above.

The invention also provides for compounds having the following structures:

where A is

where each of Y₁, Y₂ and Y₃ is independently H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocylcoalkyl, polyfluorocycloalkyl or cycloalkenyl; —F, —Cl, —Br, —I, —NO₂, —N₃, —CN, —OR₄, —OCOR₄, —COR₄, —CONHR₄, —CON(R₄)₂, —COOR₄, —CF₃ or together constitute a methylenedioxy group;

where X is S, O or NH;

where B is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl, polyfluoroalkyl, alkoxy or thioalkyl, C₂-C₇ alkenyl, —SCH₂C₆H₄OR₄, —(CH₂)_(n)C₆H₅, CH₂X(CH₂)_(n)NHR₄ or —(CH₂)_(n)NHR₄;

where n is an integer from 0 to 5;

where R₁ is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocylcoalkyl, polyfluorocycloalkyl or cycloalkenyl; —NHR₄, —N(R₄)₂ or —OR₄;

where R₂ is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocylcoalkyl, polyfluorocycloalkyl or cycloalkenyl; C₃-C₁₀ cycloalkyl-C₁-C₁₀-alkyl, C₃-C₁₀ cycloalkyl-C₁-C₁₀-monofluoroalkyl or cycloalkyl-C₁-C₁₀-polyfluoroalkyl; —CN, —CH₂XR₄, —CH₂X(CH₂)_(n)NHR₄, —(CH₂)_(n)NHR₄, —CH₂X(CH₂)_(n)N(R₄)₂, —CH₂X(CH₂)_(n)N₃ or —CH₂X(CH₂)_(n)NHCXR₆;

where R₃ is

where each R is independently H; F; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl;

where each R₄ is independently H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocylcoalkyl, polyfluorocycloalkyl or cycloalkenyl;

where R₅ is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocylcoalkyl, polyfluorocycloalkyl or cycloalkenyl; phenyl, thiophenyl, pyridyl, pyrrolyl, furanyl, imidazolyl or indolyl; —COOR₄, —COR₄, —CONHR₄, —CN, —OH or —OR₄;

where each m is independently an integer from 0 to 3;

where o is an integer from 0 to 5;

where each n is independently an integer from 0 to 5;

where R₆ is phenyl, pyridyl, thiophenyl, furanyl, pyrazinyl, pyrrolyl, naphthyl, indolyl, imidazolyl, benzfurazanyl, benzfuranyl or benzimidazolyl; C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl wherein the alkyl, monofluoroalkyl, polyfluoroalkyl, alkenyl or alkynyl is substituted with phenyl, pyridyl, thiophenyl, furanyl, pyrazinyl, pyrrolyl, naphthyl, indolyl, imidazolyl, benzfurazanyl, benzfuranyl or benzimidazolyl;

where each of Y₁, Y₂ and Y₃ is as defined above;

where Z is C₂ alkenyl or alkynyl, CH₂, O, CO, CO₂, CONR₄, S, SO, SO₂ or NR₄; and

where each D is independently CH₂, O, S, NR₄, CO or CS; or a pharmaceutically acceptable salt thereof.

Other embodiments of the invention include the compounds having the following structures:

Where A, B, Z, Y₁, Y₂, Y₃, R, R₁, R₂, R₄, R₅, R₆, n and m are as defined above.

The invention provides for the preferred embodiment having the following structure.

The invention also provides for the (−) and (+) enantiomers of all compounds of the subject application described herein. Included in this invention are pharmaceutically acceptable salts and complexes of all of the compounds described herein. The salts include but are not limited to the following acids and bases. The following inorganic acids; hydrochloric acid, hydrofluoric acid, hydrobromic acid, hydroiodic acid, sulfuric acid and boric acid. The organic acids; acetic acid, trifluoroacetic acid, formic acid, oxalic acid, malonic acid, succinic acid, fumaric acid, tartaric acid, maleic acid, citric acid, methanesulfonic acid, trifluoromethanesulfonic acid, benzoic acid, glycolic acid, lactic acid and mandelic acid. The following inorganic bases; ammonia, hydroxyethylamine and hydrazine. The following organic bases; methylamine, ethylamine, propylamine, dimethylamine, diethylamine, trimethylamine, triethylamine, ethylenediamine, hydroxyethylamine, morpholine, piperazine and guanidine. This invention further provides for the hydrates and polymorphs of all of the compounds described herein.

The invention also provides a pharmaceutical composition comprising a therapeutically effective amount of the compounds described above and a pharmaceutically acceptable carrier. In the subject invention a “therapeutically effective amount” is any amount of a compound which, when administered to a subject suffering from a disease against which the compounds are effective, causes reduction, remission, or regression of the disease. In one embodiment the therapeutically effective amount is an amount from about 0.01 mg per subject per day to about 500 mg per subject per day, preferably from about 0.1 mg per subject per day to about 60 mg per subject per day and most preferably from about 1 mg per subject per day to about 20 mg per subject per day. In the practice of this invention the “epharmaceutically acceptable carrier” is any physiological carrier known to those of ordinary skill in the art useful in formulating pharmaceutical compositions.

The invention also provides for pharmaceutical composition comprising a therapeutically effective amount of the any of the compounds described herein in combination with a therapeutically effective amount of finasteride and a pharmaceutically acceptable carrier. In one embodiment the pharmaceutical composition is a therapeutically effective amount from about 0.01 mg per subject per day to about 500 mg per subject per day of any one of the compounds described herein and a therapeutically effective amount of the finasteride of about 5 mg per subject per day. A more preferred embodiment of the pharmaceutical composition is a therapeutically effective amount from about 0.1 mg per subject per day to about 60 mg per subject per day of any one of the compounds described herein and a therapeutically effective amount of the finasteride of about 5 mg per subject per day. The most preferred embodiment of the pharmaceutical composition is a therapeutically effective amount from about 1 mg per subject per day to about 20 mg per subject per day of any one of the compounds described herein and a therapeutically effective amount of the finasteride of about 5 mg per subject per day.

In one preferred embodiment the pharmaceutical carrier may be a liquid and the pharmaceutical composition would be in the form of a solution. In another equally preferred embodiment, the pharmaceutically acceptable carrier is a solid and the composition is in the form of a powder or tablet. In a further embodiment, the pharmaceutical carrier is a gel and the composition is in the form of a suppository or cream. In a further embodiment the compound may be formulated as a part of a pharmaceutically acceptable transdermal patch.

A solid carrier can include one or more substances which may also act as flavoring agents, lubricants, solubilizers, suspending agents, fillers, glidants, compression aids, binders or tablet-disintegrating agents; it can also be an encapsulating material. in powders, the carrier is a finely divided solid which as in admixture with the finely divided active ingredient. In tablets, the active ingredient is mixed with a carrier having the necessary compression properties in suitable proportions and compacted in the shape and size desired. The powders and tablets preferably contain up to 99% of the active ingredient. Suitable solid carriers include, for example, calcium phosphate, magnesium stearate, talc, sugars, lactose, dextrin, starch, gelatin, cellulose, polyvinylpyrrolidine, low melting waxes and ion exchange resins.

Liquid carriers are used in preparing solutions, suspensions, emulsions, syrups, elixirs and pressurized compositions. The active ingredient can be dissolved or suspended in a pharmaceutically acceptable liquid carrier such as water, an organic solvent, a mixture of both or pharmaceutically acceptable oils or fats. The liquid carrier can contain other suitable pharmaceutica additives such as solubilizers, emulsifiers, buffers, preservatives, sweeteners, flavoring agents, suspending agents, thickening agents, colors, viscosity regulators, stabilizers or osmo-regulators. Suitable examples of liquid carriers for oral and parenteral administration include water (partially containing additives as above, e.g. cellulose derivatives, preferably sodium carboxymethyl cellulose solution), alcohols (including monohydric alcohols and polyhydric alcohols, e.g. glycols) and their derivatives, and oils (e.g. fractionated coconut oil and arachis oil). For parenteral administration, the carrier can also be an oily ester such as ethyl oleate and isopropyl myristate. Sterile liquid carriers are useful in sterile liquid form compositions for parenteral administration. The liquid carrier for pressurized compositions can be halogenated hydrocarbon or other pharmaceutically acceptable propellent.

Liquid pharmaceutical compositions which are sterile solutions or suspensions can be utilized by for example, intramuscular, intrathecal, epidural, intraperitoneal or subcutaneous injection. Sterile solutions can also be administered intravenously. The compounds may be prepared as a sterile solid composition which may be dissolved or suspended at the time of administration using sterile water, saline, or other appropriate sterile injectable medium. Carriers are intended to include necessary and inert binders, suspending agents, lubricants, flavorants, sweeteners, preservatives, dyes, and coatings.

The compound can be administered orally in the form of a sterile solution or suspension containing other solutes or suspending agents, for example, enough saline or glucose to make the solution isotonic, bile salts, acacia, gelatin, sorbitan monoleate, polysorbate 80 (oleate esters of sorbitol and its anhydrides copolymerized with ethylene oxide) and the like.

The compound can also be administered orally either in liquid or solid composition form. Compositions suitable for oral administration include solid forms, such as pills, capsules, granules, tablets, and powders, and liquid forms, such as solutions, syrups, elixirs, and suspensions. Forms useful for parenteral administration include sterile solutions, emulsions, and suspensions.

Optimal dosages to be administered may be determined by those skilled in the art, and will vary with the particular compound in use, the strength of the preparation, the mode of administration, and the advancement of the disease condition. Additional factors depending on the particular subject being treated will result in a need to adjust dosages, including subject age, weight, gender, diet, and time of administration.

The invention further provides a method of treating a subject suffering from benign prostatic hyperplasia which comprises administering to the subject an amount of the one the compounds described above effective to treat benign prostatic hyperplasia.

The invention also provides a method of treating a subject suffering from high intraocular pressure which comprises administering to the subject an amount of any of the compounds described above effective to lower intraocular pressure.

This invention also provides a method of treating a subject suffering a disorder associated with high cholesterol which comprises administering to the subject an amount of any of the compounds described above effective to inhibit cholesterol synthesis.

This invention also provides a method of treating a disease which is susceptible to treatment by antagonism of the α_(1c) receptor which comprises administering to the subject an amount of any the compounds described above effective to treat the disease.

This invention also provides a method of treating a subject suffering from impotency which comprises administering to the subject an amount of any of the compounds described above effective to treat impotency.

This invention also provides a method of treating a subject suffering from sympathetically mediated pain which comprises administering to the subject an amount of any of the compounds described above effective to treat sympathetically mediated pain.

This invention also provides a method of treating a subject suffering from cardiac arrhythmia which comprises administering to the subject an amount of any of the compounds described above effective to treat cardiac arrhythmia.

This invention also provides a method of treating a subject suffering from benign prostatic hyperplasia which comprises administering to the subject an amount of any of the compounds described above in combination with a 5 alpha-reductase inhibitor effective to treat benign prostatic hyperplasia. The 5-alpha reductase inhibitor is finasteride. The dosage administered to the subject is about 0.01 mg per subject day to 50 mg per subject per day of finasteride in combination with an α_(1c) antagonist.

A preferred dosage administered to the subject is about 0.2 mg per subject per day to 10 mg per subject per day of finasteride in combination with an α_(1c) antagonist. A more preferred dosage administered to the subject is about 1 mg per subject per day to 7 mg per subject per day of finasteride in combination with an α_(1c) antagonist. The most preferred dosage administered to the subject is about 5 mg per subject per day of finasteride in combination with an α_(1c) antagonist.

One skilled in the art will readily appreciate that appropriate biological assays will be used to determine the therapeutic potential of the claimed compounds for the treating the above noted disorders.

This invention will be better understood from the Experimental Details which follow. However, one skilled in the art will readily appreciate that the specific methods and results discussed are merely illustrative of the invention as described more fully in the claims which follow thereafter.

EXPERIMENTAL DETAILS

For Examples 1-17 Scheme 1 describes the general synthetic preparation. All NMRs were obtained using a 300 MHz GE QEPLUS NMR machine.

Example 1

1,6-Dihydro-5-methoxycarbonyl-2-[{(4-methoxyphenyl)methyl}thio]-4-methyl-6-(4-nitrophenyl)-1-{N-[3-(4,4-diphenylpiperidin-1-yl)propyl]}carboxamido pyrimidine.

a. 4,4-Diphenylpiperidine hydrochloride. A mixture of 4-piperidone monohydrate hydrochloride (15.0 g, 0.0976 mol) and AlCl₃ (130 g, 0.976 mol, 10.0 eq) in anhydrous benzene (600 mL) were stirred at reflux for 4 hours. The mixture was cooled to room temperature, poured into ice (300 g) and water (50 mL), and filtered. The solid was washed with toluene and dried to afford 19.2 g (72%) of an off-white solid, which was characterized spectroscopically.

b. 3-(4,4-Diphenylpiperidin-1-yl)propionitrile. To a suspension of 4,4-diphenylpiperidine hydrochloride (0.195 g, 0.712 mmol) in EtOH (1.5 mL) was added Et₃N (0.25 mL, 1.8 mmol, 2.6 eq) followed by acrylonitrile (0.13 mL, 2.01 mmol, 2.8 eq). The resulting solution was stirred at room temperature under argon for 15 min and then concentrated. Water was added, and the mixture was extracted with EtOAc (3×10 mL). The combined organic extracts were dried (MgSO₄) and concentrated to give 170 mg (87%) of a tan solid, which was characterized spectroscopically and used in the next reaction without purification.

c. 3-(4,4-Diphenylpiperidin-1-yl)propylamine. To a stirred solution of 3-(4,4-diphenylpiperidin-1-yl)propio-nitrile (2.00 g, 6.89 mmol) in anhydrous THF (20 mL) under argon was added a solution of BH₃ in THF (1.0 M, 24.1 mL, 24 mmol, 3.5 eq) at room temperature. The mixture was refluxed for 4.5 hours and then cooled to room temperature. Aqueous HCl (6 N, 50 mL) was added and stirring was continued for 1 hour. The mixture was basified to pH 9 by addition of 6 N aq. NaOH, extracted with CH₂Cl₂ (3×10 mL), dried (MgSO₄) and concentrated. The residue was purified by flash chromatography (SiO₂, EtOAc-MeOH-isopropylamine 9:1:0 to 4:1:0.2) to give 1.35 g (66%) of tan solid, which was characterized spectroscopically.

d. 2-(4-Methoxybenzyl)-2-thiopseudourea hydrochloride. To a well-stirred suspension of thiourea (7.6 g, 0.1 mol) in THF (50 mL) at 0° C., 4-methoxybenzyl chloride (16 g, 0.1 mol) was added in 10 min and the mixture was allowed to warm to room temperature. After 2 hours the mixture was heated to 65° C. and kept at that temperature for 5 hours. It was cooled to room temperature and diluted with diethyl ether (200 mL). The white precipitate formed was filtered and dried (22.5 g, 96%); m. p. 161-163° C.

e. Methyl 2-{(4-nitrophenyl)methylene}-3-oxobutyrate. A mixture of 4-nitrobenzaldehyde (15.1 g, 0.1 mol), methyl acetoacetate (12.773 g, 0.11 mol), piperidine (0.41 g, 476 mL, 4.8 mmol), and acetic acid (0.288 g, 274 mL, 4.8 mmol) in 2-propanol (400 mL) was stirred at room temperature for 48 hours. The white solid, methyl 2-{(4-nitrophenyl)methylene}-3-oxobutyrate, formed was filtered, washed with 2-propanol (2×50 mL) and dried (21.80 g, 93%).

f. 1,6-Dihydro-5-methoxycarbonyl-2-[{(4-methoxyphenyl)methyl}thio]-4-methyl-6-(4-nitrophenyl)pyrimidine. A mixture of methyl 2-{(4-nitrophenyl)methylene}-3-oxobutyrate (8.96 g, 0.04 mol), 2-(4-methoxybenzyl)-2-thiopseudourea hydrochloride (9.28 g, 0.04 mol), and NaOAc (3.28 g, 0.04 mol) in DMF (100 mL) was stirred and heated at 70-75° C. for 4.5 hours. she mixture was cooled, poured into ice-water (300 mL), extracted with EtOAc (2×400 mL). The combined EtOAc extracts were washed with 10% NaHCO₃ solution (2×60 mL), brine (100 mL), and dried (MgSO₄). Solvent was evaporated and the crude product was purified by flash column chromatography on silica gel using 10% through 30% EtOAc in hexane as the gradient eluent, to leave the product as an oil, which on trituration with EtOAc/hexane became a yellow solid (11.4 g, 66.7%); m.p. 138-139° C.; ¹H-NMR (CDCl₃): δ 2.15 (s, 3 H), 3.62 (s, 3 H), 3.72 (s, 3 H), 4.05, 5.78 (s, d, J=3 Hz, 1 H), 4.08, 4.20 (AB q, J=12.5 Hz, 2 H), 4.21, 6.40 (s, d, J=3 Hz, 1 H), 6.66 (2 d, J=8.5 Hz, 2 H), 7.08 (2 d, J=8.5 Hz, 2 H), 7.37 (2 d, J=8.8 Hz, 2 H) 8.7 (2 d, J=8.8 Hz, 2 H); Anal. Calcd. for C₂₁H₂₁N₃O₅S: C, 59.00; H, 4.95; N, 9.83. Found: C, 59.02; H, 4.93; N, 9.77.

g. 1,6-Dihydro-5-methoxycarbonyl-2-[{(4-methoxyphenyl)methyl}thio]-4-methyl-6-(4-nitrophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine. To a well-stirred mixture of 1,6-dihydro-5-methoxycarbonyl-2-[{(4-methoxyphenyl)methyl}thio]-4-methyl-6-(4-nitrophenyl)pyrimidine (4.5 g, 0.0105 mol), NaHCO₃ (3.69 g, 0.044 mol), CH₂Cl₂ (200 mL), and water (50 mL) at 0-5° C., 4-nitrophenyl chloroformate (2.4 g, 0.0119 mol) was added in 5 min and the mixture was allowed to warm to room temperature. After 10 hours, the TLC analysis of the reaction mixture showed the presence of a small amount of starting pyrimidine, therefore, more 4-nitrophenyl chloroformate (1.65 g, 0.0032 mol) was added and the stirring continued for an additional 4 hours. The two layers were separated, the CH₂Cl₂ layer was washed with saturated aqueous NaHCO₃ solution (3×50 mL), dried (MgSO₄), and the solvent evaporated. The residue was recrystallized from CH₂Cl₂ and hexane to give the product as white crystals (5.5 g, 88.4%); m.p. 156-157° C.; ¹H-NMR (CDCl₃): δ 2.53 (s, 3 H), 3.70 (s, 3 H), 3.81 (s, 3 H), 4.06, 4.36 (AB q, J=13.5 Hz, 2 H), 6.30 (s, 1 H), 6.78 (d, J=8.7 Hz, 2 H), 7.17 (d, J=8.5 Hz, 2 H), 7.20 (d, J=8.7 Hz, 2 H), 7.32 (d, J=8.8 Hz, 2 H), 7.97 (d, J=8.8 Hz, 2 H), 8.25 (d, J=8.8 Hz, 2 H); Anal. Calcd. for C₂₈H₂₄N₄O₉S: C, 56.75; H, 4.08; N, 9.45. Found: C, 56.49; H, 4.28; N, 9.25.

h. 1,6-Dihydro-5-methoxycarbonyl-2-[{(4-methoxyphenyl)methyl}thio]-4-methyl-6-(4-nitrophenyl)-1-{N-[3-(4,4-diphenylpiperidin-1-yl)prop-yl]}carboxamidopyrimidine. To a stirred solution of 1,6-dihydro-5-methoxycarbonyl-2-[{(4-methoxyphenyl)methyl}thio]-4-methyl-6-(4-nitrophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine (0.592 g, 1 mmol) in anhydrous THF (10 mL) at room temperature under argon atmosphere, a solution of 3-[4,4-diphenylpiperidin-1-yl]propylamine (0.441 g, 1.5 mmol, 1.5 eq) in THF (5 mL) was added and the stirring continued for 1 hours. Solvent was evaporated from the reaction mixture and the residue was redissolved in CH₂Cl₂ (50 mL), washed with 5% NaHCO₃ (3×25 mL), brine (50 mL), and dried (MgSO₄). Solvent was evaporated and the residue was purified by flash chromatography on silica gel using 10% methanol in EtOAc as the eluent to give the desired product as an oil, which on trituration with hexane and drops of EtOAc became a white powder (0.32 g, 43%); m.p. 79-80° C.; ¹H-NMR (CDCl₃): δ 1.61-1.82 (m, 4 H), 2.27 (s, 3 H), 2.30-2.51 (m, 8 H), 3.19-3.36 (m, 1 H), 3.42-3.60 (m, 1 H), 3.68 (s, 3 H), 3.76 (s, 3 H), 3.95, 4.22 (AB q, J=13.6 Hz, 2 H), 6.16 (s, 1 H), 6.70 (d, J=8.6 Hz, 2 H), 7.04 (d, J=8.6 Hz, 2 H), 7.11-7.29 (m, 12 H), 7.68 (br t, 1 H, NH), 7.91 (d, J=8.8 Hz, 2 H); Anal. Calcd. for C₄₂H₄₅N₅O₆S. 0.33 CH₂Cl₂: C, 65.52; H, 5.93; N, 9.03. Found: C, 65.52; H, 6.01; N, 9.20.

Example 2

1,6-Dihydro-5-methoxycarbonyl-2-[{(4-methoxyphenyl)methyl}thio]-4-methyl-6-(4-nitrophenyl)-1-{N-[3-(4-phenylpiperidin-1-yl)propyl]}carboxamidopyrimidine.

a. 3-(4-Phenylpiperidin-1-yl)propionitrile. Acrylonitrile (3.1 mL, 44 mmol, 2.5 eq) was added to a solution of 4-phenylpiperidine (3.0 g, 18 mmol) in EtOH (40 mL) and the mixture was stirred at room temperature for 1.5 hours. The volatiles were removed to give 3.8 g of pure product (brown oil, 99%), which was characterized spectroscopically.

b. 3-(4-Phenylpiperidin-1-yl)propylamine. To a stirred solution of 3-(4-phenylpiperidin-1-yl)propionitrile (5.1 g, 24 mmol) in anhydrous THF (20 mL) under argon was added a solution of BH₃ in THF (1.0 M, 83 mL, 83 mmol, 3.5 eq) at room temperature. The mixture was refluxed for 4.5 hours and then cooled to room temperature. Aqueous HCl (6 N, 130 mL) was added and stirring was continued for 2 hours at 50-70° C. The mixture was basified to pH 9 by addition of 6 N aq. NaOH and extracted with EtOAc (100 mL) and CH₂Cl₂ (3×100 mL). The combined organic extracts were dried (MgSO₄) and concentrated. The residue was dissolved in CH₂Cl₂ (20 mL) and treated with HCl in ether (1.0 M, 50 mL). The solvents were removed, ether (250 mL) was added, the mixture was filtered, and the filter cake was washed with ether. Water (60 mL) was added to the resulting white solid, the pH was adjusted to 10-11 with 1 N NaOH, and the aqueous phase was extracted with CH₂Cl₂ (3×50 mL). The combined extracts were dried (MgSO₄) and the solvents evaporated to give 4.5 g (87%) of pure product (light brown solid), which was characterized spectroscopically.

c. 1,6-Dihydro-5-methoxycarbonyl-2-[{(4-methoxyphenyl)methyl}thio]-4-methyl-6-(4-nitrophenyl)-1-{N-[3-(4-phenylpiperidin-1-yl)propyl]}carboxamidopyrimidine. This compound was prepared from 1,6-dihydro-5-methoxycarbonyl-2-[{(4-methoxyphenyl)methyl}thio]-4-methyl-6-(4-nitrophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine (0.77 g, 1.3 mmol), 3-[4-phenylpiperidin-1-yl]propylamine (0.34 g, 1.56 mmol, 1.2 eq) and purified using similar conditions described in Example 1 (0.63 g, 72%); m.p. 123-124° C.; ¹H-NMR (CDCl₃): δ 1.65-2.10 (m, 8 H), 2.41 (s, 3 H), 2.41-2.55 (m, 3 H), 2.99-3.06 (m, 2 H), 3.2-3.35 (m, 1 H), 3.45-3.60 (m, 1 H), 3.67 (s, 3 H), 3.75 (s, 3 H), 4.10, 4.33 (AB q, J=13.6 Hz, 2 H), 6.19 (s, 1 H), 6.71 (d, J=8.6 Hz, 2 H), 7.09 (d, J=8.6 Hz, 2 H), 7.20-7.34 (m, 7 H), 7.97 (br t, 1 H, NH), 7.97 (d, J=8.8 Hz, 2 H); Anal. Calcd. for C₃₆H₄₁N₅O₆S. 0.25 CH₂Cl₂: C, 62.82; H, 6.04; N, 10.11. Found: C, 62.54; H, 6.13; N, 10.03.

Example 3

1-{N-[3-(4-Cyano-4-phenylpiperidin-1-yl)propyl]}carboxamido-1,6-dihydro-5-methoxycarbonyl-2-[{(4-methoxyphenyl)methyl}thio]-4-methyl-6-(4-nitrophenyl)pyrimidine.

a. 3-(4-Cyano-4-phenylpiperidinlyl)propylamine. 4-Cyano-4-phenylpiperidine hydrochloride (5.01 g, 22.5 mmol) was added to water (100 mL), and the solution was basified to pH 10-11 by addition of 6 N aqueous NaOH. The mixture was extracted with CH₂Cl₂ (3×100 mL). The combined organic extracts were dried (MgSO₄) and concentrated. To the residue were added 3-bromopropylamine hydrobromide (4.92 g, 22.5 mmol), anhydrous K₂CO₃ (3.42 g, 24.8 mmol, 1.10 eq), and 1,4-dioxane (100 mL). The mixture was stirred at reflux for 24 hours under a CaSO₄ drying tube. The solvent was evaporated, and the product was purified by flash chromatography (SiO₂, CHCl₃/MeOH/2 M NH₃ in MeOH (100:8:4 to 100:20:8) to give 3.23 g (59%) of colorless oil, which was characterized spectroscopically.

b. 1-{N-[3-(4-Cyano-4-phenylpiperidin-1-yl)propyl]}carboxamido-1,6-dihydro-5-methoxycarbonyl-2[{(4-methoxy-phenyl)methyl}thio]-4-methyl-6-(4-nitrophenyl)pyrimidine. This compound was prepared from 1,6-dihydro-5-methoxycarbonyl-2-[{(4-methoxyphenyl)methyl}thio]-4-methyl-6-(4-nitrophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine (0.592 g, 1 mmol), 3-[4-cyano-4-phenylpiperidin-1-yl]propylamine (0.292 g, 1.2 mmol, 1.2 eq) and purified using similar conditions described in Example 1 (0.445 g, 64%); m.p. 143-144° C.; ¹H-NMR (CDCl₃): δ 1.70-1.86 (m, 2 H), 2.02-2.09 (m, 4 H), 2.38 (s, 3 H), 2.41-2.56 (m, 4 H), 2.95-3.02 (m, 2 H), 3.24-3.40 (m, 1 H), 3.42-3.58 (m, 1 H), 3.68 (s, 3 H), 3.76 (s, 3 H), 4.08, 4.23 (AB q, J=13.5 Hz, 2 H), 6.23 (s, 1 H), 6.72 (d, J=8.6 Hz, 2 H), 6.94 (br t, 1 H, NH), 7.08 (d, J=8.6 Hz, 2 H), 7.29 (d, J=8.7 Hz, 2 H), 7.33-7.49 (m, 5 H), 7.94 (d, J=8.8 Hz, 2 H); Anal. Calcd. for C₃₇H₄₀N₆O₆: C, 63.78; H, 5.79; N, 12.06. Found: C, 63.86; H, 5.90; N, 11.92.

Example 4

1,6-Dihydro-5-methoxycarbonyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-2-[{(4-methoxyphenyl)methyl)}thio]-4-methyl-6-(4-nitrophenyl)pyrimidine.

a. 4-Methoxycarbonyl-4-phenylpiperidine. To a stirred solution of H₂SO₄ (16 mL) in MeOH (400 mL), 4-phenyl-4-piperidinecarboxylic acid 4-methylbenzenesulfonate (37.7 g, 0.1 mole) was added and the mixture was stirred and refluxed for 8 hours. Excess methanol was evaporated at reduced pressure and the residue was poured into a mixture of ice and 6 N NaOH. The pH was adjusted to 10-11 by adding more 6 N NaOH and extracted with CH₂Cl₂ (3×150 mL). The combined CH₂Cl₂ extracts were dried (MgSO₄) and the solvent evaporated to leave the desired product as a viscous oil. The product (20.2 g, 92%) was used without further purification.

b. 3-(4-Methoxycarbonyl-4-phenylpiperidin-1-yl)propylamine. A mixture of 4-methoxycarbonyl-4-phenylpiperidine (8.5 g, 0.039 mol), 3-bromopropylamine hydrobromide (12.7 g, 0.058 mol), potassium carbonate (13.475 g, 0.0957 mole), and KI (3.24 g, 0.0195 mol) in 1,4-dioxane (200 mL) was stirred and refluxed for 24 hours. Dioxane was evaporated at reduced pressure, the residue was treated with ice-cold 6 N NaOH (400 mL) and extracted with CH₂Cl₂ (4×120 mL). Solvent was evaporated from the combined dried (K₂CO₃) extracts and the residue was purified by column chromatography on silica gel using CHCl₃/MeOH/2 M NH₃ in MeOH (20:2:1) as the eluent to afford the product as a viscous oil (7.8 g, 72%).

c. 1,6-Dihydro-5-methoxycarbonyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-2-[{(4-methoxyphenyl)methyl}thio]-4-methyl-6-(4-nitrophenyl)pyrimidine. This compound was prepared from 1,6-dihydro-5-methoxycarbonyl-2-[{(4-methoxyphenyl)methyl}thio]-4-methyl-6-(4-nitrophenyl)-1-[(4-nitrophenyl-oxy)carbonyl]pyrimidine (1.0 g, 1.69 mmol), 3-[4-methoxycarbonyl-4-phenylpiperidin-1-yl]propylamine (0.56 g, 2.03 mmol, 1.2 eq) and purified using similar conditions described in Example 1 (1.085 g, 88%); m.p. 140-141° C.; ¹H-NMR (CDCl₃): δ 1.62-1.74 (m, 2 H), 1.82-2.18 (m, 4 H), 2.21 (s, 3 H), 2.35-2.58 (m, 4 H), 2.75-2.89 (m, 2 H), 3.18-3.30 (m, 1 H), 3.42-3.58 (m, 1 H), 3.61 (s, 3 H), 3.66 (s, 3 H), 3.75 (s, 3 H), 3.91, 4.15 (AB q, J=13.6 Hz, 2 H), 6.14 (s, 1 H), 6.69 (d, J=8.6 Hz, 2 H), 7.02 (d, J=8.6 Hz, 2 H), 7.20-7.37 (m, 7 H), 7.56 (br t, 1 H, NH), 7.90 (d, J=8.8 Hz, 2 H); Anal. Calcd. for C₃₈H₄₃N₅O₈S: C, 62.54; H, 5.94; N, 9.60. Found: C, 62.41; H, 6.06; N, 9.34.

Example 5

5-Methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1-{N-[3-(4,4-diphenyl-piperidin-1-yl)propyl]}carboxamido-1,2,3,6-tetrahydro-2-thioxo-pyrimidine. To a stirred solution of 1,6-dihydro-6-methoxycarbonyl-2-[{(4-methoxyphenyl)methyl}thio]-4-methyl-6-(4-nitrophenyl)-1-{N-[3-(4,4-diphenylpiperidin-1-yl)propyl]}carboxamidopyrimidine (0.14 g, 0.187 mmol) and ethanethiol (0.5 mL) in CH₂Cl₂ (5 mL) at 5° C. under argon, TFA (0.5 mL) was added and the mixture was allowed to warm to room temperature. After 3 hours, solvents were evaporated completely, the residue was redissolved in EtOAc (10 mL), washed with 5% NaHCO₃ (5×1 mL) and dried (MgSO₄). Solvent was evaporated and the residue was purified by column chromatography using 1:1 hexane/EtOAc to 100% EtOAc as gradient eluent. The oily product was crystallized from hexane and EtOAc (0.096 g, 82%); m.p. 130-131° C.; ¹H-NMR (CDCl₃): δ 1.65-1.80 (m, 2 H), 2.31 (s, 3 H), 2.31-2.49 (m, 10 H), 3.25-3.55 (m, 2 H), 3.76 (s, 3 H), 7.01 (s, 1 H), 7.09-7.29 (m, 6 H), 7.41 (d, J=8.2 Hz, 2 H), 8.11 (d, J=8.8 Hz, 2 H), 9.76 (br t, 1 H, NH); Anal. Calcd. for C₃₄H₃₇N₅O₆S. 0.3 H₂O: C, 64.50; H, 5.89; N, 11.06. Found: C, 64.45; H, 6.05; N, 10.87.

Example 6

5-Methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1-{N-[3-(4-phenyl-piperidin-1-yl)propyl]}carboxamido-1,2,3,6-tetrahydro-2-thioxo-pyrimidine. This compound was prepared from 1,6-dihydro-3-{N-[3-(4-phenylpiperidin-1-yl)propyl]}carboxamido-6-methoxycarbonyl-2-[{(4-methoxyphenyl)methyl}thio]-6-(4-nitrophenyl)-4-methylpyrimidine (0.15 g, 0.223 mmol) using the procedure described in Example 5 and purified by flash column chromatography (0.102 g, 83%); m.p. 134-135° C.; ¹H-NMR (CDCl₃): δ 1.72-1.94 (m, 4 H), 1.96-2.11 (m, 2 H), 2.36 (s, 3 H), 3.0-3.09 (m, 2 H), 3.32-3.49 (m, 2 H), 3.76 (s, 3 H), 7.06 (s, 1 H), 7.17-7.30 (m, 6 H), 7.42 (d, J=8.7 Hz, 2 H), 8.11 (d, J=8.8 Hz, 2 H), 9.80 (br t, 1 H, NH); Anal. Calcd. for C₂₈H₃₃N₅O₅S: C, 60.96; H, 6.03; N, 12.70. Found: C, 60.63; H, 5.78; N, 12.55.

Example 7

1-{N-[3-(4-Cyano-4-phenylpiperidin-1-yl)propyl]}carboxamido-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1,2,3,6-tetrahydro-2-thioxopyrimidine. This compound was prepared from 1-{N-[3-(4-cyano-4-phenylpiperidin-1-yl)propyl]}carboxamido-1,6-dihydro-6-methoxycarbonyl-2-[{(4-methoxyphenyl)methyl}thio]-6-(4-nitrophenyl)-4-methylpyrimidine (0.15 g, 0.215 mmol) using the procedure described in Example 5 and purified by flash column chromatography (0.118 g, 95%); m.p. 137-138° C.; ¹H-NMR (CDCl₃): δ 1.69-1.85 (m, 2 H), 2.07-2.20 (m, 4 H), 2.37 (s, 3 H), 2.37-2.60 (m, 4 H), 2.96-3.06 (m, 2 H), 3.31-3.86 (m, 2 H), 3.76 (s, 3 H), 7.09 (s, 1 H), 7.31-7.49 (m, 7 H), 7.92 (br s, 1 H, NH), 8.12 (d, J=8.8 Hz, 2 H), 9.84 (br t, 1 H, NH); Anal. Calcd. for C₂₉H₃₂N₆O₅S: C, 60.53; H, 5.74; N, 14.49. Found: C, 60.53; H, 5.74; N, 14.48.

Example 8

5-Methoxycarbonyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-4-methyl-6-(4-nitrophenyl)-1,2,3,6-tetrahydro-2-thioxopyrimidine This compound was prepared from 1,6-dihydro-6-methoxycarbonyl-3-{N-[4-methoxycarbonyl-phenyl-piperidin-1-yl]propyl}carboxamido-2-[{(4-methoxyphenyl)methyl}thio]-6-(4-nitrophenyl)-4-methylpyrimidine (0.730 g, 1 mmol) using the procedure described in Example 5 and purified by flash column chromatography (0.57 g, 94%); m.p. 135-136° C.; ¹H-NMR (CDCl₃): δ 1.62-2.13 (m, 6 H), 2.32 (s, 3 H), 2.33-2.39 (m, 4 H), 2.76-2.84 (m, 2H), 3.34-3.43 (m, 2 H), 3.61 (s, 3 H), 3.75(s, 3 H), 7.04 (s, 1 H), 7.21-7.35 (m, 5 H), 7.40 (d, J=8.6 Hz, 2 H), 7.82 (br s, 1 H, NH), 8.10 (d, J=8.9 Hz, 2 H), 9.76 (br t, 1 H, NH); Anal. Calcd. for C₃₀H_(35N) ₅O₇S: C, 59.10; H, 5.79; N, 11.49. Found: C, 59.08; H, 5.91; N, 11.31.

Example 9

1-{N-[3-(4-(4-Methoxyphenyl)-4-phenylpiperidin-1-yl)propyl]}carboxamido-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1,2,3,6-tetrahydro-2-thioxopyrimidine.

a. 4-(4-Methoxyphenyl)-4-phenylpiperidine. 4-Hydroxy-4-phenylpiperidine (5.00 g, 28.2 mmol) was added to a suspension of AlCl₃ (18.8 g, 0.141 mol, 5.00 eq) in anhydrous anisole (100 mL). The mixture was stirred at room temperature for 1 hours and then heated to 50° C. for 3.5 hours. It was cooled to room temperature and poured cautiously into ice-water. The mixture was basified to pH 11 by addition of 6 N aqueous NaOH, and extracted with EtOAc (3×75 mL). The combined organic extracts were applied directly to a flash chromatography column, which was eluted with CH₂Cl₂/0.67 M NH₃ in MeOH (4:1) to afford 1.683 g (22%) of light yellow oil, which was characterized spectroscopically.

b. 3-[4-(4-Methoxyphenyl)-4-phenylpiperidin-1-yl]propionitrile. Acrylonitrile (1.03 mL, 15.7 mmol, 2.50 eq) was added at 0° C. to a solution of 4-(4-methoxyphenyl)-4-phenylpiperidine (1.68 g, 6.28 mmol) in EtOH (20 mL) and the resulting solution was stirred for 1.5 hours at room temperature. After removal of the solvent, the residue was purified by flash chromatography (SiO₂, EtOAc-CHCl₃ 1:3) to give 1.41 g (70%) of colorless oil, which was characterized spectroscopically.

c. 3-[4-(4-Methoxyphenyl)-4-phenylpiperidin-1-yl]propylamine. To a stirred solution of 3-[4-(4-methoxyphenyl)-4-phenylpiperidin-1-yl]propionitrile (1.41 g, 4.40 mmol) in anhydrous THF (10 mL) under argon was added a solution of BH₃ in THF (1.0 M, 11.0 mL, 2.5 eq) at room temperature. The mixture was refluxed for 4.5 hours and then cooled to room temperature. Aqueous HCl (6 N, 15 mL) was added and stirring was continued for 2 h at 55-60° C. The mixture was basified to pH 9 by addition of 6 N aq. NaOH and extracted with CH₂Cl₂ (3×75 mL). The combined organic solutions were dried (MgSO₄) and concentrated. The residue was dissolved in CH₂Cl₂ (10 mL) and treated with HCl in ether (1.0 M, 9.0 mL, 2.0 eq). The solvents were removed, ether (30 mL) was added, the mixture was filtered, and the filter cake was washed with ether (2×10 mL). Water (20 mL) was added to the resulting white solid, the pH was adjusted to 10 with 1 N NaOH, and the aqueous phase was extracted with CH₂Cl₂ (3×40 mL). The combined organic extracts were dried (MgSO₄) and concentrated to give 610 mg (43%) of white solid, which was characterized spectroscopically.

d. 1-{N-[3-(4-(4-Methoxyphenyl)-4-phenylpiperidin-1-yl)propyl]}carboxamido-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1,2,3,6-tetrahydro-2-thioxopyrimidine. To a stirred mixture of 1,6-dihydro-5-methoxycarbonyl-2-[{(4-methoxyphenyl)methyl}thio]-4-methyl-6-(4-nitrophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine (0.592 g, 1 mmol) and K₂CO₃ (0.276 g, 2 mmol) in anhydrous THF (10 mL) at room temperature under argon atmosphere, a solution of 3-[4-(4-methoxyphenyl)-4-phenylpiperidin-1-yl]propylamine (0.390 g, 1.2 mmol, 1.2 eq) in THF (10 mL) was added and the stirring was continued for 1 hour. Solvent was evaporated from the reaction mixture and the residue was redissolved in CH₂Cl₂ (50 mL), washed with 5% NaHCO₃ (3×25 mL), brine (50 mL), and dried (MgSO₄). The CH₂Cl₂ solution was filtered and cooled to 5° C. To this, ethanethiol (0.5 mL) and TFA (0.5 mL) were added and the mixture was stirred and allowed to warm to room temperature. After 3 hours, solvents were evaporated completely, the residue was redissolved in EtOAc (10 mL) washed with 5% NaHCO₃ (5×1 mL), and dried (MgSO₄). Solvent was evaporated and the residue was purified by column chromatography using 1:1 hexane/EtOAc to 100% EtOAc as gradient eluent. The oily product was crystallized from hexane and EtOAc (0.41 g, 62%); m.p. 120-121° C.; ¹H-NMR (CDCl₃): δ 1.60-1.80 (m, 2 H), 2.31 (s, 3 H), 2.31-2.51 (m, 8 H), 3.32-3.43 (m, 2 H), 3.75 (s, 3 H), 3.76 (s, 3 H), 6.77 (d, J=8.8 Hz, 2 H), 7.02 (s, 1 H), 7.12 (d, J=8.6 Hz, 2 H), 7.20-7.27 (m, 6 H), 7.41 (d, J=8.6 Hz, 2 H), 8.11 (d, J=8.8 Hz, 2 H), 9.76 (br t, 1 H, NH); Anal. Calcd. for C₃₅H₃₉N₅O₆S: C, 63.91; H, 5.98; N, 10.65. Found: C, 64.19; H,6.22; N, 10.36.

Example 10

a. 4-Ethoxycarbonyl-4-phenylpiperidine. To a stirred solution of H₂SO₄ (1.62 g, 16.56 mmol) in EtOH (200 mL), 4-phenyl-4-piperidine-carboxylic acid 4-methylbenzenesulfonate (25 g, 66.23 mmol) was added and the mixture was stirred and refluxed for 12 hours. Excess ethanol was evaporated at reduced pressure and the residue was poured into a mixture of ice and 6 N NaOH. The pH was adjusted to 10-11 by adding more 6 N NaOH and extracted with CH₂Cl₂ (3×100 mL). The combined CH₂Cl₂ extracts were dried (MgSO₄) and the solvent evaporated to leave the desired product as a colorless viscous oil, the ¹H-NMR showed it to be pure (14.68 g, 95%) and was used without any further purification.

b. 3-(4-Ethoxycarbonyl-4-phenylpiperidin-1-yl)propylamine. A mixture of 4-ethoxycarbonyl-4-phenylpiperidine (30.5 g, 0.131 mol), 3-bromopropylamine hydrobromide (42.93 g, 0.196 mol), potassium carbonate (36.14 g, 0.241 mole), and KI (10.8 g, 0.065 mol) in 1,4-dioxane (500 mL) was stirred and refluxed for 24 hours. Dioxane was evaporated at reduced pressure, the residue was treated with ice-cold 6 N NaOH (400 mL) and extracted with CH₂Cl₂ (4×120 mL). Solvent was evaporated from the combined dried (K₂CO₃) CH₂Cl₂ extracts and the residue was purified by column chromatography on silica gel using CHCl₃/MeOH/2 M NH₃ in MeOH (20:2:1) as the eluent to afford the product as a viscous oil (24.2 g, 83.3%).

c. 1-{N-[3-(4-Ethoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1,2,3,6-tetra-hydro-2-thioxopyrimidine. This compound was prepared from 1,6-dihydro-5-methoxycarbonyl-2-[{(4-methoxyphenyl)methyl}thio]-4-methyl-6-(4-nitrophen-yl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine (0.592 g, 1 mmol), K₂CO₃ (0.276 g, 2 mmol), 3-[4-ethoxycarbonyl-4-phenylpiperidin-1-yl]propylamine (0.350 g, 1.2 mmol, 1.2 eq), ethanethiol (0.5 mL), and TFA (0.5 mL) using the procedure described in Example 10 and purified by flash column chromatography (0.295 g, 47%); m.p. 125-126° C.; ¹H-NMR (CDCl₃): δ 1.13 (t, J=7 Hz, 3 H), 1.62-1.80 (m, 2 H), 1.87-2.0 (m, 2 H), 2.06-2.18 (m, 2 H), 2.31 (s, 3 H), 2.34-2.39 (m, 2 H), 2.50-2.55 (m, 2 H), 2.79-2.83 (m, 2 H), 3.30-3.51 (m, 2 H), 3.74 (s, 3 H), 4.07 (q, J=7 Hz, 2 H), 7.03 (s, 1 H), 7.18-7.36 (m, 6 H), 7.40 (d, J=8.8 Hz, 2 H), 8.08 (d, J=8.8 Hz, 2 H), 9.78 (br t, 1 H, NH); Anal. Calcd. for C₃₁H₃₇N₅O₇S: C, 59.70; H, 5.98; N, 11.23. Found: C, 59.55; H, 5.99; N, 11.43.

Example 11

1,6-Dihydro-1-{N-[3-(4,4-diphenylpiperidin-1-yl)propyl]}carboxamido-2-methoxy-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)pyrimidine. To a stirred mixture of 1,6-dihydro-2-methoxy-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine (0.940 g, 2 mmol) and K₂CO₃ (0.552 g, 4 mmol) in anhydrous THF (20 mL) at room temperature under argon atmosphere, a solution of 3-[4,4-diphenylpiperidin-1-yl]propylamine (0.882 g, 3 mmol, 1.5 eq) in THF (5 mL) was added and the stirring was continued for 1 hour. Solvent was evaporated from the reaction mixture, the residue was redissolved in CH₂Cl₂ (50 mL), washed with 5% NaHCO₃ (3×25 mL), brine (50 mL), and dried (MgSO₄). Solvent was evaporated and the residue was purified by flash chromatography on silica gel using 10% methanol in EtOAc as the eluent to give the desired product as an oil, which on trituration with hexane and drops of EtOAc became a white powder (1.10 g, 88%); m.p. 95-96° C.; ¹H-NMR (CDCl₃): δ 1.61-1.71 (m, 2 H), 2.26-2.33 (m, 2 H), 2.38 (s, 3 H), 2.39-2.50 (m, 8 H), 3.20-3.41 (m, 2 H), 3.65 (s, 3 H), 3.89 (s, 3 H), 6.65 (s, 1 H), 6.84 (br t, 1 H, NH), 7.08-7.29 (m, 10 H), 7.40 (d, J=8.7 Hz, 2 H), 8.03 (d, J=8.6 Hz, 2 H); Anal. Calcd. for C₃₅H₃₉N₅O₆. 0.75 CH₂Cl₂: C, 62.28; H, 5.92; N, 10.16. Found: C, 62.23; H, 5.76; N, 10.12.

Example 12

5-Methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1-{N-[3-(4,4-diphenyl-piperidin-1-yl)propyl]}carboxamido-2-oxo-1,2,3,6-tetrahydropyrimid-ine.

a. 1,6-Dihydro-5-methoxycarbonyl-2-methoxy-4-methyl-6-(4-nitro-phenyl)pyrimidine. A mixture of methyl 2-{(4-nitrophen-yl)methylene}-3-oxobutyrate (12.46 g, 0.05 mol), O-methylisourea hydrogen sulfate (10.32 g, 0.06 mol), and NaOAc (9.84 g, 0.06 mol) in DMF (50 mL) was stirred and heated at 70-75° C. for 4 hours. The mixture was cooled and poured into ice-water (300 mL). The precipitate formed was filtered, washed with water, and dried. The crude product was purified by flash column chromatography on silica gel using 10% through 30% EtOAc in hexane as the gradient eluent (9.8 g, 64%). The ¹H-NMR analysis of the product showed it to be a 19:1 mixture of the amine/imine tautomers which was used as such in the next step. ¹H-NMR (CDCl₃): δ 2.32, 2.38 (2 s, 3 H), 3.59, 3.70 (2 s, 3 H), 3.70, 3.85 (2 s, 3 H), 5.40, 5.66 (s, d, J=3 Hz, 1 H), 5.50, 6.08 (s, d, J=3 Hz, 1 H), 7.43, 7.45 (2 d, J=9 Hz, 2 H), 8.10, 8.11 (2 d, J=9 Hz, 2 H).

b. 1,6-Dihydro-2-methoxy-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine. To a well-stirred mixture ofl,6-dihydro-2-methoxy-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)pyrimidine (5.7 g, 0.0187 mol), NaHCO₃ (6.27 g, 0.074 mol), CH₂Cl₂ (200 mL), and water (50 mL) at 0-5° C., 4-nitrophenyl chloroformate (3.76 g, 0.0186 mol) was added in 5 min and the mixture was allowed to warm to room temperature. After 10 hours, the TLC analysis of the reaction mixture showed the presence of a small amount of starting pyrimidine, therefore, more 4-nitrophenyl chloroformate (0.65 g, 0.0032 mol) was added and the stirring continued for an additional 4 hours. The two layers were separated, the CH₂Cl₂ layer was washed with saturated aqueous NaHCO₃ solution (3×50 mL), dried (MgSO₄), and the solvent evaporated. The residue was recrystallized from CH₂Cl₂ and hexane to give the product as white crystals (12.8 g, 89%); ¹H-NMR (CDCl₃): δ 2.48 (s, 3 H), 3.69 (s, 3 H), 3.94 (s, 3 H), 6.34 (s, 1 H), 7.36 (d, J=9.1 Hz, 2 H), 7.46 (d, J=8.7 Hz, 2 H), 8.14 (d, J=8.7 Hz, 2 H), 8.26 (d, J=9.1 Hz, 2 H); m.p. 168-169° C. Anal. Calcd. for C₂₁H₁₈N₄O₉: C, 53.62; H, 3.86; N, 11.91. Found: C, 53.69; H, 3.92; N, 11.85.

c. 5-Methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1-{N-[3-(4,4-di-phenylpiperidin-1-yl)propyl]}carboxamido-2-oxo-1,2,3,6-tetrahydro-pyrimidine. To a stirred solution of 1,6-dihydro-2-methoxy-6-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1-{N-[3-(4,4-diphenylpiperidin-1-yl)propyl]}carboxamidopyrimidine (0.208 g, 0.33 mmol) in THF (10 mL) at 5° C. under argon, 3 N HCl (6 mL) was added and the mixture was allowed to warm to room temperature. After 2 hours, solvents were evaporated completely, the residue was treated with 40 mL of 10% NaHCO₃, the product was extracted with CH₂Cl₂ (2×15 mL) and the combined extracts were dried (MgSO₄). Solvent was evaporated and the residue was crystallized from hexane and EtOAc (0.20 g, 97%); m.p. 197-198° C.; ¹H-NMR (CDCl₃): δ 1.63-1.67 (m, 2 H), 2.23-2.28 (m, 2 H), 2.34 (s, 3 H), 2.37-2.42 (m, 8 H), 3.20-3.41 (m, 2 H), 3.69 (s, 3 H), 6.75 (s, 1 H), 7.08-7.26 (m, 11 H), 7.46 (d, J=8.7 Hz, 2 H), 8.08 (d, J=8.7 Hz, 2 H), 8.77 (br t, 1 H, NH); Anal. Calcd. for C₃₄H₃₇N₅O₆: C, 66.76; H, 6.10; N, 11.45. Found: C, 66.48; H, 5.97; N, 11.25.

Example 13

1-{N-[3-(4-(4-Methoxyphenyl)-4-phenylpiperidin-1-yl)propyl}]carboxamido-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-2-oxo-1,2,3,6-tetrahydropyrimidine. To a stirred mixture of 1,6-dihydro-2-meth-oxy-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine (0.47 g, 1 mmol) and K₂CO₃ (0.552 g, 4 mmol) in anhydrous THF (10 mL) at room temperature under argon atmosphere, a solution of 3-[4-(4-methoxyphenyl)-4-phenylpiperidin-1-yl]propyl-amine (0.390 g, 1.2 mmol, 1.2 eq) in THF (10 mL) was added and the stirring was continued for 2 hours. The solid was removed by filtration and the solution was cooled to 0-5° C. 6N HCl (2 mL) was added to the solution and stirring was continued. After 3 hours, solvents were evaporated completely, the residue was redissolved in CH₂Cl₂ (20 mL), washed with 10% NaHCO₃ (2×10 mL), and dried (MgSO₄). Solvent was evaporated and the residue was purified by column chromatography using 1:1 hexane/EtOAc to 100% EtOAc as gradient eluent. The oily product was crystallized from hexane and EtOAc (0.55 g, 86%); m.p. 100-102° C.; ¹H-NMR (CDCl₃): δ 1.65-1.80 (m, 2 H), 2.26-2.31 (m, 2 H), 2.35 (s, 3 H), 2.39-2.44 (m, 6 H), 3.18-3.40 (m, 2 H), 3.69 (s, 3 H), 3.73 (s, 3 H), 6.75 (s, 1 H), 7.60 (d, J=8.7 Hz, 2 H), 6.84 (br s, 1 H, NH), 7.10 (d, J=8.7 Hz, 2 H), 7.18-7.26 (m, 5 H), 7.46 (d, J=8.6 Hz, 2 H), 8.08 (d, J=8.6 Hz, 2 H), 8.78 (br t, 1 H, NH); Anal. Calcd. for C₃₅H₃₉N₅O₇. 0.12 CH₂Cl₂. 0.12 EtOAc: C, 64.54; H, 6.12; N, 10.57. Found: C, 64.44; H, 6.12; N, 10.28.

Example 14

1-{N-[3-(4-Methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-2-oxo-1,2,3,6-tetrahydropyrimidine (Scheme 2).

To a stirred mixture of 1,6-dihydro-2-methoxy-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine (0.47 g, 1 mmol), K₂CO₃ (0.276 g, 2 mmol) in anhydrous THF (10 mL) at room temperature under argon atmosphere, a solution of 3-[4-methoxycarbonyl-4-phenylpiperidin-1-yl]propylamine (0.332 g, 1.2 mmol, 1.2 eq) in THF (10 mL) was added and the stirring was continued for 2 hours. The solid was removed by filtration and the solution was cooled to 0-5° C. To this, 6 N HCl (2 mL) was added and the stirring continued. After 3 hours, solvents were evaporated completely, the residue was redissolved in CH₂Cl₂ (20 mL) washed with 10% NaHCO₃ (2×10 mL), and dried (MgSO₄). Solvent was evaporated and the residue was purified by column chromatography using 1:1 hexane/EtOAc to 100% EtOAc as gradient eluent. The oily product was crystallized from hexane and EtOAc (0.55 g, 86%); m.p. 180-181° C.; ¹H-NMR (CDCl₃): δ 1.60-1.80 (m, 2 H), 1.85-1.95 (m, 2 H), 2.03-2.10 (m, 2 H), 2.28-2.33 (m, 2 H), 2.35 (s, 3 H), 2.48-2.50 (m, 2 H), 3.20-3.40 (m, 2 H), 3.60 (s, 3 H), 3.68 (s, 3 H), 6.75 (s, 1 H), 7.20-7.34 (m, 6 H), 7.46 (d, J=8.8 Hz, 2 H), 8.07 (d, J=8.8 Hz, 2 H), 8.78 (br t, 1 H, NH); Anal. Calcd. for C₃₀H₃₅N₅O₈: C, 60.70; H, 5.94; N, 11.80. Found: C, 60.71; H, 5.99; N, 11.43.

Examples 14a & 14b

(+)-1-{N-[3-(4-Methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-2-oxo-1,2,3,6-tetrahydropyrimidine and (−)1-{N- C₃-(4-Methoxycarbanyl-4-phenyl-piperidin-1-yl)propyl]}carboxamido-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-2-oxo-1,2,3,6-tetrahydropyrimidine (Scheme 3).

a. (−)-1,6-Dihydro-2-methoxy-5-methoxycarbonyl-4-methyl-6-(4-nitro-phenyl)-1-{N-[(2-phenyl)ethyl]}carboxamidopyrimidine and (+)-1,6-Dihydro-2-methoxy-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)1-{N-[(2-phennyl)ethyl]}carboxamidopyrimidine. To a stirred solution of (±)-1,6-dihydro-2-methoxy-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine (2.66 g, 5.6 mmol) in an hydrous THF (80 mL) at room temperature under argon atmosphere, a solution of (S)-(−)-α-methylbenzylamine (0.82 g, 6.78 mmol, 1.2 eq) in THF (5 mL) was added and the stirring was continued for 6 hours. Solvent was evaporated from the reaction mixture, the residue was redissolved in CH₂Cl₂ (50 mL), washed with 5% NaHCO₃ (3×25 mL), brine (50 mL), and dried (MgSO₄). Solvent was evaporated and the residue was purified by flash chromatography on silica gel using 5% to 30% EtOAc in hexane as the gradient eluent. The first major product to elute was (−)-1,6-dihydro-2-methoxy-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1-{N-[(2-phenyl)ethyl]}carboxamidopyrimidine and this compound was crystallized from isopropyl ether (0.85 g, 33.6%); m.p. 119-120° C.; [α]_(D)=−329.32 (CH₂Cl₂, 10.3 g/100 mL); ¹H-NMR (CDCl₃): δ 1.47 (d, J=7 Hz, 3 H), 2.40 (s, 3 H), 3.61 (s, 3 H), 3.95 (s, 3 H), 4.96 (quint, J=6.5 Hz, 2 H), 6.66 (s, 1 H), 6.82 (d, J=6.8 Hz, 1 H, NH), 7.22-7.36 (m, 5 H), 7.43 (d, J=8.6 Hz, 2 H), 8.09 (d, J=8.6 Hz, 2 H); Anal. Calcd. for C₂₃H₂₄N₄O₆: C, 61.06; H, 5.35; N, 12.38. Found: C, 60.85; H, 5.13; N, 12.42. The second major compound to elute was (+)-1,6-dihydro-2-methoxy-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1-{N-[(2-phenyl)ethyl]}carboxamidopyrimidine and this compound was crystallized from isopropyl ether (0.92 g, 36.4%); m.p. 138-140° C.; [α]_(D)=+171.81 (CH₂Cl₂, 11.31 g/100 mL); ¹H-NMR (CDCl₃): δ 1.47 (d, J=7 Hz, 3 H), 2.42 (s, 3 H), 3.644 (s, 3 H), 3.917 (s, 3 H), 4.989 (quint, J=6.5 Hz, 2 H), 6.70 (s, 1 H), 6.81 (d, J=6.8 Hz, 1 H, NH), 7.22-7.35 (m, 5 H), 7.36 (d, J=8.6 Hz, 2 H), 8.04 (d, J=8.6 Hz, 2 H); Anal. Calcd. for C₂₃H₂₄N₄O₆: C, 61.06; H, 5.35; N, 12.38. Found: C, 60.95; H, 5.20; N, 12.38.

b. (+)-1-{N-[3-(4-Methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-2-oxo-1,2,3,6-tetrahydropyrimidine. A solution of (+)-1,6-dihydro-2-methoxy-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1-{N-[(2-phenyl)ethyl]}carboxamidopyrimidine (0.226 g, 0.5 mmol) and 1,8-diazabicyclo[5.4.0]-unde-7-ene (DBU) (0.076 g, 0.5 mmol) in CH₂Cl₂ (10 mL) was stirred and refluxed for 4 hours and the solvent evaporated. The product was purified by column chromatography using 30% EtOAc in hexane as the eluent. The product was found to be a mixture of the amine-imine tautomers (0.120 g, 78.7%); [α]_(D)=+14.5 (CH₂Cl₂, 6 g/100 mL).

To a well-stirred solution of (+)-1,6-dihydro-5-methoxycarbonyl-2-methoxy-4-methyl-6-(4-nitrophenyl)pyrimidine (0.12 g, 0.393 mmol) and pyridine (0.5 mL) in CH₂Cl₂ (10 mL) at 0-5° C., 4-nitrophenyl chloroformate (0.095 g, 0.472 mmol) was added in 5 min and the mixture was allowed to warm to room temperature. After 2 h, saturated aqueous NaHCO₃ solution (10 mL) was added and the stirring continued for 30 min. The two layers were separated, the CH₂Cl₂ layer was washed with saturated aqueous NaHCO₃ solution (3×5 mL), dried (Na₂SO₄), and the solvent evaporated. The residue was redissolved in THF (10 mL) and mixed with K₂CO₃ (0.11 g, 0.8 mmol). To this, a solution of 3-[4-methoxycarbonyl-4-phenylpiperidin-1-yl]propylamine (0.138 g, 0.5 mmol) in THF (5 mL) was added and the mixture was stirred for 2 hours. The solid was removed by filtration and the solution was cooled to 0-5° C. To this, 6 N HCl (0.5 mL) was added and the stirring continued. After 3 hours, solvents were evaporated completely, the residue was redissolved in CH₂Cl₂ (20 mL), washed with 10% NaHCO₃ (4×5 mL), and dried (MgSO₄). Solvent was evaporated and the residue was purified by column chromatography using 1:1 hexane/EtOAc to 100% EtOAc as gradient eluert. The oily product was crystallized from hexane and EtOAc (0.19 g, 82%); m.p. 138-140° C.; [α]_(D)=+108 (CH₂Cl₂, 6.65 g/100 mL); ¹H-NMR (CDCl₃): δ 1.60-1.80 (m, 2 H), 1.85-1.95 (m, 2 H), 2.03-2.10 (m, 2 H), 2.28-2.33 (m, 2 H), 2.35 (s, 3 H), 2.48-2.50 (m, 2 H), 3.20-3.40 (m, 2 H), 3.60 (s, 3 H), 3.68 (s, 3 H), 6.75 (s, 1 H), 7.20-7.34 (m, 5 H), 7.45 (d, J=8.8 Hz, 2 H), 7.60 (br s, 1 H, N H), 8.07 (d, J=8.8 Hz, 2 H), 8.78 (br t, 1 H, NH); Anal. Calcd. for C₃₀H₃₅N₅O₈. 0.2 CH₂Cl₂. 0.2 EtOAc: C, 59.27; H, 5.94; N, 11.15. Found: C, 59.07; H, 5.76; N, 10.99.

c. (−)-1-{N-[3-(4-Methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-2-oxo-1,2,3,6-tetrahydropyrimidine. A solution of (−)-1,6-dihydro-2-methoxy-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1-{N-[(2-phenyl)ethyl]}carboxamidopyrimidine (0.35 g, 0.774 mmol) and 1,8-diazabicyclo[5.4.0]-unde-7-ene (DBU) (0.117 g, 0.774 mmol) in CH₂Cl₂ (10 mL) was stirred and refluxed for 8 hours and the solvent evaporated. The product was purified by column chromatography using 30% EtOAc in hexane as the eluent. The product, (−)-1,6-dihydro-5-methoxycarbonyl-2-methoxy-4-methyl-6-(4-nitrophenyl)pyrimidine, was found to be a mixture of the amine-imine tautomers (0.170 g, 72%). To a well-stirred solution of (−)-1,6-dihydro-5-methoxycarbonyl-2-methoxy-4-methyl-6-(4-nitrophenyl)pyrimidine (0.152 g, 0.5 mmol) and pyridine (0.5 mL) in CH₂Cl₂ (10 mL) at 0-5° C., 4-nitrophenyl chloroformate (0.121 g, 0.6 mmol) was added in 5 min and the mixture was allowed to warm to room temperature. After 2 hours, saturated aqueous NaHCO₃ solution (10 mL) was added and the stirring continued for 30 min. The two layers were separated, the CH₂Cl₂ layer was washed with saturated aqueous NaHCO₃ solution (3×5 mL), dried (Na₂SO₄), and the solvent evaporated. The residue was redissolved in THF (10 mL) and mixed with K₂CO₃ (0.165 g, 1.2 mmol). To this, a solution of 3-[4-methoxycarbonyl-4-phenylpiperidin-1-yl]propylamine (0.166 g, 0.6 mmol) in THF (5 mL) was added and the mixture was stirred for 2 hours. The solid was removed by filtration and the solution was cooled to 0-5° C. To this, 6 N HCl (0.5 mL) was added and the stirring continued. After 3 hours, solvents were evaporated completely, the residue was redissolved in CH₂Cl₂ (20 mL), washed with 10% NaHCO₃ (4×5 mL), and dried (MgSO₄). Solvent was evaporated and the residue was purified by column chromatography using 1:1 hexane/EtOAc to 100% EtOAc as gradient eluent. The oily product was crystallized from hexane and EtOAc (0.19 g, 64%); m.p. 138-140° C.; [α]_(D)=−106 (CH₂Cl₂, 3.95 g/100 mL); ¹H-NMR (CDCl₃): δ 1.60-5.80 (m, 2 H), 1.85-1.95 (m, 2 H), 2.03-2.10 (m, 2 H), 2.28-2.33 (m, 2 H), 2.35 (s, 3 H), 2.48-2.50 (m, 2 H), 3.20-3.40 (m, 2 H), 3.60 (s, 3 H), 3.68 (s, 3 H), 6.75 (s, 1 H), 7.20-7.34 (m, 6 H), 7.46 (d, J=8.8 Hz, 2 H), 8.07 (d, J=8.8 Hz, 2 H), 8.78 (br t, 1 H, NH); Anal. Calcd. for C₃₀H₃₅N₅O₈. 0.4 CH₂Cl₂: C, 58.18; H, 5.75; N, 11.16. Found: C, 58.25; H, 5.67; N, 10.98.

Example 15

1-{N-[3-(4-Ethoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-2-oxo-1,2,3,6-tetrahydropyrimidine. To a stirred mixture of 1,6-dihydro-2-methoxy-5-methoxycarbonyl-4-methyl-6-(4-nitrophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine (0.235 g, 0.5 mmol), K₂CO₃ (0.138 g, 1 mmol) in anhydrous THF (10 mL) at room temperature under argon atmosphere, a solution of 3-[4-ethoxycarbonyl-4-phenylpiperidin-1-yl]propylamine (0.174 g, 0.6 mmol, 1.2 eq) in THF (5 mL) was added and the stirring was continued for 4.5 h. The solid was removed by filtration and the solution was cooled to 0-5° C. To this, 6 N HCl (0.5 mL) was added and the stirring continued. After 1 hour, solvents were evaporated completely, the residue was redissolved in CH₂Cl₂ (20 mL), washed with 1 N NaHCO₃ (2×10 mL), and dried (MgSO₄). Solvent was evaporated and the residue was purified by column chromatography using 1:1 hexane/EtOAc to 100% EtOAc as gradient eluent. The oily product was crystallized from hexane and EtOAc (0.182 g, 60%); m.p. 79-80° C.; ¹H-NMR (CDCl₃): δ 1.13 (t, J=7 Hz, 3 H), 1.62-1.78 (m, 2 H), 1.87-2.0 (m, 2 H), 2.06-2.18 (m, 2 H), 2.2-2.31 (m, 2 H), 2.37(s, 3 H), 2.50-2.55 (m, 2 H), 2.72-2.80 (m, 2 H), 3.25-3.40 (m, 2 H), 3.68 (s, 3 H), 4.07 (q, J=7 Hz, 2 H), 6.75 (s, 1 H), 7.18-7.36 (m, 6 H), 7.48 (d, J=8.7 Hz, 2 H), 8.11 (d, J=8.7 Hz, 2 H), 8.79 (br t, 1 H, NH); Anal. Calcd. for C₃₁H₃₇N₅O₈. 0.5 C₆H₁₂. 1.25 H₂O: C, 62.71; H, 7.06; N, 11.55. Found: C, 62.90; H, 7.20; N, 11.33.

Example 16

5-Benzyloxycarbonyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-4-methyl-6-(3,4-methylenedioxyphenyl)-2-oxo-1,2,3,6-tetrahydropyrimidine.

a. Benzyl 2-{(3,4-methylenedioxyphenyl)methylene}-3-oxobutyrate. A mixture of 3,4-methylenedioxybenzaldehyde (15.013 g, 0.1 mol), benzyl acetoacetate (20.18 g, 0.105 mol), piperidine (0.41 g, 476 mL, 4.8 mmol), and acetic acid (0.288 g, 274 mL, 4.8 mmol) in 2-propanol (500 mL) was stirred at room temperature for 48 hours. The white solid, benzyl 2-{(3,4-methylenedioxyphenyl)methylene}-3-oxobutyrate, formed was filtered, washed with 2-propanol (2×50 mL) and dried (29.84 g, 92%); m.p. 137-138° C.

b. 5-Benzyloxycarbonyl-1,6-dihydro-2-methoxy-4-methyl-6-(3,4-methylenedioxyphenyl)pyrimidine. A mixture of benzyl 2-{(3,4-methylenedioxyphenyl)methylene}-3-oxobutyrate (16.266 g, 0.35 mol), O-methylisourea hydrogen sulfate (10.32 g, 0.06 mol), and NaHCO₃ (8.4 g, 0.1 mol) in EtQH (400 mL) was stirred and heated at 85-90° C. for 48 h. The solid was removed by filtration and ethanol was evaporated from, the filtrate. The residue was redissolved in EtOAc (300 mL), washed with water (2×100 mL), dried (Na₂SO₄), and the solvent evaporated. The crude product was purified by flash column chromatography on silica gel using 10% through 30% EtOAc in hexane as the gradient eluent, to leave the product as a viscous oil (11.8 g, 62%). The ¹H-NMR analysis of the product showed it co be a 1:1 mixture of the amine/imine tautomers and was used as such in the next step.

c. 5-Benzyloxycarbonyl-1,6-dihydro-2-methoxy-4-methyl-6-(3,4-methylenedioxyphenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine. To a well-stirred solution of 5-benzyloxycarbonyl-1,6-dihydro-2-methoxy-4-methyl-6-(3,4-methylenedioxyphenyl)pyrimidine (10.0 g, 0.0263) and pyridine (5 mL) in CH₂Cl₂ (500 mL) at 0-5° C., 4-nitrophenyl chloroformate (7.56 g, 0.038 mol) was added in 5 min and the mixture was allowed to warm to room temperature. After 16 hours, saturated aqueous NaHCO₃ solution (100 mL) was added and the stirring continued for 30 min. The two layers were separated, the CH₂Cl₂ layer was washed with saturated aqueous NaHCO₃ solution (3×50 mL), dried (Na₂SO₄), and the solvent evaporated. The residue on trituration with isopropyl ether gave the product as white crystals (12.8 g, 89%); m.p. 146-147° C.; ¹H-NMR (CDCl₃): δ 2.46 (s, 3 H), 3.93 (s, 3 H), 5.19, 5.92 (AB q, J=12.6 Hz, 2 H), 5.92 (s, 2 H), 6.22 (s, 1 H), 6.68-6.78 (m, 3 H), 7.15-7.29 (m, 5 H), 7.30 (d, J=9.1 Hz, 2 H), 8.22 (d, J=9.1 Hz, 2 H); Anal. Calcd. for C₂₈H₂₃N₃O₉. 0.25 H₂O. 0.25 CH₂Cl₂: C, 59.40; H, 4.23; N, 7.36. Found: C, 59.42; H, 4.07; N, 7.30.

d. 5-Benzyloxycarbonyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-4-methyl-6-(3,4-methylenedioxyphenyl)-2-oxo-1,2,3,6-tetrahydropyrimidine. To a stirred mixture of 5-benzyloxycarbonyl-1,6-dihydro-2-methoxy-4-methyl-6-(3,4-methylenedioxyphenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine (1.091 g, 2 mmol), K₂CO₃ (0.552 g, 4 mmol) in anhydrous THF (20 mL) at room temperature under argon atmosphere, a solution of 3-[4-methoxycarbonyl-4-phenylpiperidin-1-yl]propylamine (0.663 g, 2.4 mmol, 1.2 eq) in THF (10 mL) was added and the stirring was continued for 2 hours. The solid was removed by filtration and the solution was cooled to 0-5° C. To this, 6 N HCl (2 mL) was added and the stirring continued. After 3 hours, the solvent was evaporated completely, the residue was redissolved in CH₂Cl₂ (20 mL), washed with 10% NaHCO₃ (2×10 mL), and dried (MgSO₄). Solvent was evaporated and the residue was purified by column chromatography using 1:1 hexane/EtOAc to 100% EtOAc as gradient eluent, to afford the pure product as a white foam (0.55 g, 866); m.p. 100-102° C.; ¹H-NMR (CDCl₃): δ 1.64-1.80 (m, 2 H), 1.80-1.99 (m, 2 H), 2.0-2.09 (m, 2 H), 2.24-2.29 (m, 2 H), 2.33 (s, 3 H), 2.48-2.50 (m, 2 H), 2.76-2.83 (m, 2 H), 3.21-3.37 (m, 2 H), 3.60 (s, 3 H), 5.02, 5.18 (AB q, J=12.5 Hz, 2 H), 5.88 (s, 2 H), 6.61-6.78 (m, 3 H), 6.80 (s, 1 H), 7.14-7.39 (m, 11 H), 8.75 (br t, 1 H, NH); Anal. Calcd. for C₃₇H₄₀N₄O₈. 0.3 H₂O: C, 65.92; H, 6.07; N, 8.31. Found: C, 65.95; H, 6.00; N, 8.18.

Example 17

5-Methoxycarbonyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-4-methyl-6-(3,4-methylenedioxyphenyl)-2-oxo-1,2,3,6-tetrahydropyrimidine. To a stirred solution of 5-benzyloxycarbonyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-4-methyl-6-(3,4-methylenedioxyphenyl)-2-oxo-1,2,3,6-tetrahydropyrimidine (0.320 g, 0.48 mmol) in methanol (20 mL) and HCOOCH (1 mL) at 0-5° C., 10% Pd—C (0.26 g) was added in portions and the cooling bath was removed. TLC analysis of the reaction mixture at frequent intervals showed the completion of the reaction after 2 hours. The catalyst was removed by filtration and the solvent was evaporated to leave 1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-4-methyl-6-(3,4-methylenedioxyphenyl)-2-oxo-1,2,3,6-tetrahydropyrimidine-5-carboxylic acid as a white solid (0.275 g, 99%). The product was used in the next step without any further purification and characterization. A mixture of 1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-4-methyl-6-(3,4-methylenedioxyphenyl)-2-oxo-1,2,3,6-tetrahydropyrimidine-5-carboxylic acid (0.2 g, 0.346 mmol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.382 g, 2 mmol), and 4-(N,N-dimethylamino)pyridine (0.488 g, 4 mmol), in methanol (20 mL) was stirred and refluxed for 5 h and the solvent evaporated. The residue was redissolved in CH₂Cl₂ (15 mL), washed with saturated aqueous ammonium chloride solution (3×10 mL), and dried (Na₂SO₄). Evaporation of the solvent left the pure product as white powder (0.202 g, 99%); m.p. 139-141° C.; ¹H-NMR (CDCl₃): δ 1.62-1.80 (m, 2 H), 1.95-2.20 (m, 4 H), 2.35 (s, 3 H), 2.30-2.55 (m, 4 H), 2.76-2.90 (m, 2 H), 3.21-3.40 (m, 2 H), 3.61 (s, 3 H), 3.67 (s, 3 H), 5.89 (s, 2 H), 6.61-6.82 (m, 3 H), 6.63 (s, 1 H), 7.21-7.35 (m, 6 H), 8.79 (br t, 1 H, NH); Anal. Calcd. for C₃₁H₃₆N₄O₈. 0.3 EtOAc: C, 62.47; H, 6.25; N, 9.05. Found: C, 62.64; H, 6.25; N, 8.87.

Example 18

5-(2-Cyanoethoxycarbonyl)-4-ethyl-1,6-dihydro-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-2-methoxy-6-(4-nitrophenyl)pyrimidine.

a. 2-Cyanoethyl 3-{(4-nitrophenyl)methylene}-4-oxopentanoate. A mixture of ethyl propionylacetate (25 g, 0.173 mol) and 3-hydroxypropionitrile (18.48 g, 0.26 mol) was stirred and heated at 200-205° C. for 2 hours and the ethanol formed was removed by distillation. The residue was subjected to high vacuum distillation and the fraction distilling at 120-125° C. at 0.4 mm Hg was collected to get 2-cyanoethyl propionylacetate (21.5 g, 73.4%). A mixture of 4-nitrobenzaldehyde (14.46 g, 0.957 mol), 2-cyanoethyl propionylacetate (17.0 g, 0.1005 mol), piperidine (0.41 g, 476 mL, 4.8 mmol), and acetic acid (0.288 g, 274 mL, 4.8 mmol) in 2-propanol (400 mL) was stirred at room temperature for 24 h. The white solid, 2-cyanoethyl 3-{(4-nitrophenyl)methylene}-4-oxopentanoate, was filtered, washed with 2-propanol (2×50 mL) dried and used without further purification (Yield: 28.34 g, 97%); m.p. 98-100° C.

b. 5-(2-Cyanoethoxycarbonyl)-1,6-dihydro-2-methoxy-4-ethyl-6-(4-nitrophenyl)pyrimidine. A mixture of 2-cyanoethyl 3-{(4-nitrophenyl)methylene}-4-oxopentancate (5.00 g, 16.54 mmol), O-methylisourea hydrogen sulfate (3.422 g, 19.85 mmol), and NaHCO₃ (2.78 g, 33.08 mol) in EtOH (70 mL) was stirred and heated at 85-90° C. for 5 hours. The solid was removed by filtration and ethanol was evaporated from the filtrate. The residue was redissolved in EtOAc (300 mL), washed with water (2×100 mL), dried (Na₂SO₄), and the solvent evaporated. The crude product was purifwied by flash column chromatooraphy on silica gel using CHCl₃/methanol (30:1) as the eluent, to leave the product as a white solid (2.95 g, 50%). The ¹H-NMR analysis of the product showed it to be a 5:1 mixture of the amine/imine tautomers and was used as such in the next step.

c. 5-(2-Cyanoethoxycarbonyl)-4-ethyl-1,6-dihydro-2-methoxy-6-(4-nitrophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine. To a well-stirred solution of 5-(2-cyanoethoxycarbonyl)-4-ethyl-1,6-dihydro-2-methoxy-6-(4-nitrophenyl)pyrimidine (2.64 g, 7.36 mmol) and pyridine (1.19 mL, 14.72 mmol) in CH₂Cl₂ (100 mL) at 0-5° C., 4-nitrophenyl chloroformate (1.485 g, 7.36 mmol) was added in 5 min and the mixture was allowed to warm to room temperature. After 16 h, saturated aqueous NAHCO₃ solution (25 mL) was added and the stirring continued for 30 min. The two layers were separated, the CH₂Cl₂ layer was washed with saturated aqueous NAHCO₃ solution (3×50 mL), dried (Na₂SO₄), and the solvent evaporated. The crude product was purified by flash column chromatography on silica gel using CHCl₃/EtOAc (25:1) as the eluent to give the product as a viscous oil (1.70 g, 44%); ¹H-NMR (CDCl₃): δ 1.24 (t, J=7 Hz, 3 H), 2.61-2.68 (m, 2 H), 2.88-2.92 (m, 2 H), 3.97 (s, 3 H), 4.32 (t, J=7 Hz, 2 H), 6.34 (s, 1 H), 7.37 (d, J=9.2 Hz, 2 H), 7.50 (d, J=8.7 Hz, 2 H), 8.18 (d, J=8.7 Hz, 2 H), 8.28 (d, J=9.2 Hz, 2 H).

d. 5-(2-Cyanoethoxycarbonyl)-4-ethyl-1,6-dihydro-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-2-methoxy-6-(4-nitrophenyl)pyrimidine. To a stirred mixture of 5-(2-cyanoethoxycarbonyl)-4-ethyl-1,6-dihydro-2-methoxy-6-(4-nitrophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine (0.940 g, 2 mmol) and K₂CO₃ (0.552 g, 4 mmol) in anhydrous THF (20 mL) at room temperature under argon atmosphere, a solution of 3-[4-methoxycarbonyl-4-phenylpiperidin-1-yl]propylamine (0.882 g, 3 mmol, 1.5 eq) in THF (5 mL) was added and the stirring was continued for 1 h. Solvent was evaporated from the reaction mixture, the residue was redissolved in CH₂Cl₂ (50 mL), washed with 5% NaHCO₃ (3×25 mL), brine (50 mL), and dried (MgSO₄). Solvent was evaporated and the residue was purified by flash chromatography on silica gel using 10% methanol in EtOAc as the eluent to give the desired product as an oil, which on trituration with hexane and drops of EtOAc became a whine powder (1.71 g, 80%); m.p. 62-63° C.; ¹H-NMR (CDCl₃): δ 1.16 (t, J=7.5 Hz, 3 H), 1.62-1.78 (m, 2 H), 1.80-1.84 (m, 2 H), 2.06-2.18 (m, 2 H), 2.28-2.36 (m, 2 H), 2.50-2.53 (m, 4 H), 2.58-2.63 (m, 2 H), 2.70-2.84 (m, 4 H), 3.25-3.40 (m, 2 H), 3.61 (s, 3 H), 3.92 (s, 3 H), 4.26 (m, 2 H), 6.66 (s, 1 H), 6.82 (br t, 1 H, NH), 7.22-7.33 (m, 6 H), 7.43 (d, J=7.8 Hz, 2 H), 8.10 (d, J=7.8 Hz, 2 H); Anal. Calcd. for C₃₄H₄₀N₆O₈. 0.1 C₆H₁₂. 0.5 H₂O: C, 61.44; H, 6.27; N, 12.93. Found: C, 61.44; H, 6.27; N, 12.11.

Example 19

(+)-5-Carboxamido-4-ethyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-6-(4-nitrophenyl)-2-oxo-1,2,3,6-tetrhydropyrimidine (Scheme 4).

a. 2-Cyanoethyl 3-{(4-nitrophenyl)methylene}-4-oxopentanoate. A mixture of ethyl propionylacetate (25 g, 0.173 mol) and 3-hydroxypropionitrile (18.48 g, 0.26 mol) was stirred and heated at 200-205° C. for 2 h and the ethanol formed was removed by distillation. The residue was subjected to high vacuum distillation and the fraction distilling at 120-125° C. 0.4 mm of Hg was collected to get 2-cyanoethyl propionylacetate (21.5 g, 73.4%).

A mixture of 4-nitrobenzaldehyde (14.46 g, 0.957 mol), 2-cyanoethyl propionylacetate (17.0 g, 0.1005 mol), piperidine (0.41 g, 476 mL, 4.8 mmol), and acetic acid (0.288 g, 274 mL, 4.8 mmol) in 2-propanol (400 mL) was stirred at room temperature for 24 h. The white solid, 2-cyanoethyl 3-{(4-nitrophenyl)methylene}-4-oxopentanoate, formed was filtered, washed with 2-propanol (2×50 mL) and dried (28.34 g, 97%); m.p. 98-100° C.

b. 5-(2-Cyanoethoxycarbonyl)-1,6-dihydro-2-methoxy-4-ethyl-6-(4-nitrophenyl)pyrimidine.

A mixture of 2-cyanoethyl 3-{(4-nitrophenyl)methylene}-4-oxopentanoate (5.00 g, 16.54 mmol), O-methylisourea hydrogen sulfate (3.422 g, 19.85 mmol), and NaHCO₃ (2.78 g, 33.08 mol) in EtOH (70 mL) was stirred and heated at 85-90° C. for 5 h. The solid was removed by filtration and ethanol was evaporated from the filtrate. The residue was redissolved in EtOAc (300 mL), washed with water (2×100 mL), dried (Na₂SO₄), and the solvent evaporated. The crude product was purified by flash column chromatography on silica gel using CHCl₃/methanol (30:1) as the eluent, to leave the product as a white solid (2.95 g, 50%). The ¹H-NMR analysis of the product showed it to be a 5:1 mixture of the amine/imine tautomers and was used as such in the next step.

c. 5-(2-Cyanoethoxycarbonyl)-4-ethyl-1,6-dihydro-2-methoxy-6-(4-nitrophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine.

To a well-stirred solution of 5-(2-cyanoethoxycarbonyl)-4-ethyl-1,6-dihydro-2-methoxy-6-(4-nitrophenyl)pyrimidine (2.64 g, 7.36 mmol) and pyridine (1.19 mL, 14.72 mmol) in CH₂Cl₂ (100 mL) at 0-5° C., 4-nitrophenyl chloroformate (1.485 g, 7.36 mmol) was added in 5 min and the mixture was allowed to warm to room temperature. After 16 h, saturated aqueous NaHCO₃ solution (25 mL) was added and the stirring continued for 30 min. The two layers were separated, the CH₂Cl₂ layer was washed with saturated aqueous NaHCO₃ solution (3×50 mL), dried (Na₂SO₄), and the solvent evaporated. The crude product was purified by flash column chromatography on silica gel using CHCl₃/EtOAc (25:1) as the eluent to give the product as a viscous oil (1.70 g, 44%); ¹H-NMR (CDCl₃): δ 1.24 (t, J=7 Hz, 3 H), 2.61-2.68 (m, 2 H), 2.88-2.92 (m, 2 H), 3.97 (s, 3 H), 4.32 (t, J=7 Hz, 2 H), 6.34 (s, 1 H), 7.37 (d, J=9.2 Hz, 2 H), 7.50 (d, J=8.7 Hz, 2 H), 8.18 (d, J=8.7 Hz, 2 H), 8.28 (d, J=9.2 Hz, 2 H).

d. 5-(2-Cyanoethoxycarbonyl)-4-ethyl-1,6-dihydro-2-methoxy-6-(4-nitrophenyl)-1-{N-[(2-phenyl)ethyl]}carboxamidopyrimidine. To a stirred solution of 5-(2-cyanoethoxycarbonyl)-4-ethyl-1,6-dihydro-2-methoxy-6(4-nitrophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine (17.5 g, 33.43 mmol) in anhydrous THF (200 mL) at room temperature under argon atmosphere, (R)-(+)-a-methylbenzylamine (4.86 g, 40.11 mmol) was added and the stirring was continued for 16 h. Solvent was evaporated from the reaction mixture and the residue was purified by flash chromatography on silica gel using toluene/EtOAc (20:3) as the eluent. The first major product to elute was (+)-5-(2-cyanoethoxycarbonyl)-4-ethyl-1,6-dihydro-2-methoxy-6-(4-nitrophenyl)-1-{N-[(2-phenyl)ethyl]}carboxamidopyrimidine and obtained as a viscous oil (6.11 g, 36.2%); [α]_(D)=+299.5 (c=1.95, CHCl₃); ¹H-NMR (CDCl₃): δ 1.18 (t, J=7 Hz, 3 H), 1.47 (d, J=7 Hz, 3 H), 2.61 (t, 2 H), 2.7-2.92 (m, 2 H), 3.98 (s, 3 H), 4.20-4.32 (m, 2 H), 4.96 (quint, J=6.5 Hz, 2 H), 6.66 (s, 1 H), 6.82 (d, J=6.8 Hz, 1 H, NH), 7.22-7.36 (m, 5 H), 7.45 (d, J=8.6 Hz, 2 H), 8.11 (d, J=8.6 Hz, 2 H). The second major compound to elute was (−)-5-(2-cyanoethoxycarbonyl)-4-ethyl-1,6-dihydro-2-methoxy-6-(4-nitrophenyl)-1-{N-[(2-phenyl)ethyl]}carboxamidopyrimidine and obtained as a viscous oil (5.92 g, 35%); [α]_(D)=−105.1 (c=3.9, CHCl₃); ¹H-NMR (CDCl₃): δ 1.20 (t, J=7 Hz, 3 H), 1.48 (d, J=7 Hz, 3 H), 2.62 (t, 2 H), 2.82 (q, 2 H), 3.94 (s, 3 H), 4.20-4.32 (m, 2 H), 4.96 (quint, J=6.5 Hz, 2 H), 6.69 (s, 1 H), 6.84 (d, J=6.8 Hz, 1 H, NH), 7.22-7.36 (m, 5 H), 7.39 (d, J=8.6 Hz, 2 H), 8.06 (d, J=8.6 Hz, 2 H).

e. (+)-5-(2-Cyanoethoxycarbonyl)-1,6-dihydro-2-methoxy-4-ethyl-6-(4-nitrophenyl)pyrimidine. To a stirred solution of (+)-5-(2-cyanoethoxycarbonyl)-4-ethyl-1,6-d4 hydro-2-methoxy-6-(4-nitrophenyl)-1-{N-[(2-phenyl)ethyl]}carboxamidopyrimidine (2.62 g, 5.182 mmol) in toluene (40 mL) was added 1,8-diazabicyclo[5,4,0]-undec-7-ene (0.237,1.55 mmol) at room temperature and the resulting solution was heated at 90° C. for 3.5 minutes. The solvent was evaporated and the residue was purified by flash column chromatography on silica gel using 9:1 CHCl₃/EtOAc as the eluent, to give 1.32 g (71%) of (+)-5-(2-cyanoethoxycarbonyl)-1,6-dihydro-2-methoxy-4-ethyl-6-(4-nitrophenyl)pyrimidine; [α]_(D=+)4.0 (c=3.25, CHCl₃).

f. (+)-5-(2-Cyanoethoxycarbonyl)-4-ethyl-1,6-dihydro-2-methoxy-6-(4-nitrophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine. To a well-stirred solution of 5-(2-cyanoethoxycarbonyl)-4-ethyl-1,6-dihydro-2-methoxy-6-(4-nitrophenyl)pyrimidine (1.62 g, 4.52 mmol) and 4-(N,N-dimethylamino)pyridine (0.663 g, 5.43 mmol) in CH₂Cl₂ (50 mL) at 0-5° C., 4-nitrophenyl chioroformate (1.094 g, 5.43 mmol) was added in 5 minutes and the mixture was allowed to warm to room temperature. After 3 hours the solvent evaporated and the product was purified by flash column chromatography on silica gel using CHCl₃/EtOAc (25:1) as the eluent to give the product as a white solid (2.25 g, 95%); ¹H-NMR (CDCl₃): δ 1.24 (t, J=7 Hz, 3 H), 2.61-2.68 (m, 2 H), 2.88-2.92 (m, 2 H), 3.97 (s, 3 H), 4.32 (t, J=7 Hz, 2 H), 6.34 (s, 1 H), 7.37 (d, J=9.2 Hz, 2 H), 7.50 (d, J=8.7 Hz, 2 H), 8.18 (d, J=8.7 Hz, 2 H), 8.28 (d, J=9.2 Hz, 2 H); [α]_(D)=+317.2 (c=3.9, CHCl₃).

g. (+)-5-(2-Cyanoethoxycarbonyl)-4-ethyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-6-(4-nitrophenyl)-2-oxo-1,2,3,6-tetrhydropyrimidine.

To a stirred mixture of (+)-5-(2-cyanoethoxycarbonyl)-4-ethyl-1,6-dihydro-2-methoxy-6-(4-nitrophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine (3.60 g, 6.878 mmol) in anhydrous THF (100 mL) at room temperature under argon atmosphere, a solution of 3-[4-methoxycarbonyl-4-phenylpiperidin-1-yl]propylamine (2.47 g, 8.94 mmol, 1.3 eq) in THF (10 mL) was added and the stirring was continued for 12 hours. The mixture was cooled to 0° C. and aqueous 6N hydrochloric acid (10 mL). The mixture was allowed to warm to room temperature and the stirring was continued for 5 h. Solvent was evaporated from the reaction mixture, the residue was purified by flash chromatography on silica gel using ethyl acetate (800 mL) followed by chloroform-methanol-2M ammonia in methanol (90/8/4) as the eluent, to obtain the desired product as a white powder (4.40 g, 98.5%); ¹H-NMR (CDCl₃): δ 1.23 (t, J=7.5 Hz, 3 H), 2.0-2.1 (m, 2 H), 2.40-2.95 (m, 12 H), 3.25-3.50 (m, 4 H), 3.65 (s, 3 H), 4.27-4.32 (m, 2 H), 6.64 (s, 1 H), 7.20-7.33 (m, 5 H), 7.49 (d, J=7.8 Hz, 2 H), 8.08 (d, J=7.8 Hz, 2 H), 8.70 -8.90 (m, 2 H); [α]_(D)=+112.1 (c=2.15, CHCl₃); This product was used in the next step without any additional analysis.

h. (+)-5-Carboxamido-4-ethyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-6-(4-nitrophenyl)-2-oxo-1,2,3,6-tetrhydropyrimidine.

To a stirred solution of 5-(2-cyanoethoxycarbonyl)-4-ethyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-6-(4-nitrophenyl)-2-oxo-1,2,3,6-tetrhydropyrimidine (4.40 g, 6.8 mmol) in acetone (50 mL) at 0° C., sodium hydroxide solution (1 N, 27.2 mL, 4 eq.) was added drop wise and the stirring was continued until the disappearance of the starting material (1 hour). Most of the acetone from the mixture was evaporated under reduced pressure while keeping the temperature at 0° C. and the residue was adjusted to pH 7.0 by the addition of 1N hydrochloric acid. The white precipitate of (+)-4-ethyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-6-(4-nitrophenyl)-2-oxo-1,2,3,6-tetrhydropyrimidine-5-carboxylic acid formed was filtered and dried under vacuum (3.59 g, 89%). ¹H-NMR (CDCl₃): δ 1.07 (t, J=7.5 Hz, 3 H), 1.55-1.70 (m, 2 H), 1.72-1.84 (m, 2 H), 1.84-2.15 (m, 2 H), 2.20-2.40 (m, 4 H), 2.70-2.90 (m, 2 H), 3.10-3.40 (m, 4 H), 3.51 (s, 3 H), 6.54 (s, 1 H), 7.18-7.38 (m, 6 H), 7.41 (d, J=7.8 Hz, 2 H), 8.15 (d, J=7.8 Hz, 2 H), 8.79 (br t, 1 H, N H), 10.05 (br S, 1 H, COOH); This product was used in the next step without any additional analysis.

A mixture of (+)-4-ethyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-6-(4-nitrophenyl)-2-oxo-1,2,3,6-tetrhydropyrimidine-5-carboxylic acid (0.350 g, 0.59 mmol), 1-(3-dimethylaminopropy)-3-ethylcarbodiimide hydrochloride (0.2264 g, 1.181 mmol, 2 eq.), and 4-(N,N-dimethylamino)pyridine (0.1443 g, 1.181 mmol, 2 eq) in anhydrous dichloromethane was stirred at room temperature for 2 h. To this, 40% aqueous ammonia (0.6 mL) was added and the stirring was continued for 12 h. The mixture was diluted with 100 mL of dichloromethane and washed with saturated aqueous ammonium chloride solution (3×20 mL). Solvent was evaporated from the dried (magnesium sulfate) dichloromethane solution and the residue was purified by column chromatography on silica gel using chloroform-methanol-2M ammonia in methanol (500/16/8) as the eluent, to obtain the desired product as a white powder (0.24 g, 69%); m.p. 107-109° C.; ¹H-NMR (CDCl₃): δ 1.20 (t, J=7.5 Hz, 3 H), 1.66-1.72 (m, 2 H), 1.79-2.00 (m, 3 H), 2.00-2.20 (m, 2 H), 2.29-2.35 (m, 2 H), 2.42-2.60 (m, 2 H), 2.62-2.82 (m, 3 H), 3.20-3.40 (m, 2 H), 3.60 (s, 3 H), 5.70 (br m, 2 H, NH ₂), 6.59 (s, 1 H), 7.20-7.39 (m, 6 H), 7.52 (d, J=7.8 Hz, 2 H), 8.13 (d, J=7.8 Hz, 2 H), 8.82 (t, 1 H); [α]_(D)=+115.71 (c=1.4, CHCl₃); Anal. Calcd. for C₃₀H₃₆N₆O₇. 0.8 H₂O: C, 59.36; H, 6.24; N, 13.84. Found: C, 59.47; H, 6.07; N, 13.64.

Example 20

(+)-5-Carboxamido-6-(3,4-difluorophenyl)-4-ethyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-2-oxo-1,2,3,6-tetrhydropyrimidine (Scheme 5).

a. Benzyl 3-[(3,4-difluorophenyl)methylene]-4-oxopentanoate. A solution of benzyl propionylacetate (36.3 g, 176 mmol), 3,4-dlfluorobenzaldehyde (25.0 g, 176 mmol), piperidine (0.86 mL, 9.0 mmol) and acetic acid (0.49 mL, 9.0 mmol) were refluxed with removal of water using Dean-Stark apparatus for 5 h. The solvent was removed in vacuo and the residue was dissolved in EtOAc. It was washed with water (100 mL) followed by brine (100 mL) and dried over anhydrous Na₂SO₄. Solvent was evaporated to get pale yellow syrup (60.2 g). It was used in the next step without further purification.

b. 5-(Benzyloxycarbonyl)-1,6-dihydro-2-methoxy-4-ethyl-6-(3,4-difluorophenyl)pyrimidine. A suspension of benzyl 3-[(3,4-difluorophenyl)methylene]-4-oxopentancate (16.0 g, 48.0 mmol), O-methylisourea hydrogen sulfate (16.65 g, 97.02 mmol), NaHCO₃ (16.3 g, 130.2 mmol) in DMF (190 mL) was stirred at 70° C. for 20 h. After cooling to room temperature, the mixture was filtered and the filtrate was diluted with EtOAc (300 mL) and then washed with water (4×100 mL), brine (200 mL) and dried over Na₂SO₄. After removal of solvent, the residue was purified by column chromatography (SiO₂, EtOAc/Hexane, 10%-30%) to get 5-(benzyloxycarbonyl)-1,6-dihydro-2-methoxy-4-methyl-6-(3,4-difluorophenyl)pyrimidine as a colorless oil (10.6 g, 58%). The NMR analysis showed it to be a mixture of amine/imine tautomers and was used as is in the next step.

c. 5-(Benzyloxycarbonyl)-4-ethyl-1,6-dihydro-2-methoxy-6-(3,4-difluorophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine. To a well stirred solution of 5-(benzyloxycarbonyl)-1,6-dihydro-2-methoxy-4-ethyl-6-(3,4-difluorophenyl)pyrimidine (17.0 g, 44.04 mmol) and 4-dimethylaminopyridine (6.99 g, 57.25 mmol) in CH₂Cl₂ (200 mL) was added a powder of 4-nitrophenyl chloroformate 11.54 g, 57.25 mmol) at room temperature. The reaction mixture was stirred for 12 hours and then the solvent was removed in vacuo. The residue was purified by chromatography (SiO₂, EtOAc/Hexane 10-30%) to get 5-(benzyloxycarbonyl)-4-ethyl-1,6-dihydro-2-methoxy-6-(3,4-difluorophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine as a colorless viscous oil (12.6 g, 50%). ¹H NMR (CDCl₃): δ 1.24 (t, J=7.2 Hz, 3H), 2.81-2.98 (m, 3H), 3.97 (s, 3H), 5.14 (AB_(q), δ_(A)=5.08, δ_(B)=5.20, J=12.3 Hz, 2H), 6.28 (s, 3H), 7.03-7.29 (m, 8H), 7.35 (d, J=9.2 Hz, 2H), 8.26 (d, J=9.2 Hz, 2H).

d. 5-(Benzyloxycarbonyl)-4-ethyl-1,6-dihydro-1-{N-[2-phenyl)ethyl]}carboxamido-2-methoxy-6-(3,4-difluorophenyl)pyrimidine. To a stirred mixture of 5-(benzyloxycarbonyl)-4-ethyl-1,6-dihydro-2-methoxy-6-(3,4-difluorophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine (12.6 g, 22.86 mmol) in THF (150 mL) was added a solution of R-(+)-a-methyl benzylamine (3.53 mL, 27.44 mmol) at room temperature. The stirring was continued for 12 hours. Solvent was removed in vacuo. The yellow residue was dissolved in chloroform (200 mL) and was washed with 10% K₂CO₃ solution (2×30 mL). The organic layer was dried over Na₂SO₄, filtered and solvent was removed in vacuo. The resulting mixture of diastereomers was separated by column chromatography over silica gel with 9:1 Pet. ether:Ether to 4:1 Pet. ether:Ether. First major product to elute was (+)-5-(benzyloxycarbonyl)-4-ethyl-1,6-dihydro-1-{N-[2-phenyl)ethyl]}carboxamido-2-methoxy-6-(3,4-diflurophenyl)pyrimidine. Colorless oil, Rf=0.31(4:1 Pet ether:ether), wt.=3.8 g (60%), [α]_(D)=+267.05 (c=0.76, CHCl₃) ¹H NMR: δ 1.22 (t, J=7.5 Hz, 3H), 1.52 (d, J=6.9 Hz, 3H),2.88 (q, J=6.0 Hz, 2H), 3.99 (s, 3H), 4.99 (m, 1H), 5.09 (AB_(q), δ_(A)=5.00, δ_(B)=5.19, J=12.6 Hz, 2H), 6.66 (s, 1H), 6.99-7.36 (m, 13H).; Second major product to elute was (−)-5-(benzyloxycarbonyl)-4-ethyl-1,6-dihydro-1-{N-[2-phenyl)ethyl]}carboxamido-2-methoxy-6-(3,4-diflurophenyl)pyrimidine. Colorless oil. Rf=0.22(4:1 Pet ether:ether), wt.=3.2 g (51.2%), [α]_(D)=−146.89 (c=0.38, CHCl₃), ¹H NMR: δ 1.22 (t, J=7.2 Hz, 3H), 1.49 (d, J=6.6 Hz, 3H),2.88 (q, J=6.0 Hz, 2H), 3.94 (s, 3H), 5.03 (m, 1H), 5.11 (AB_(q), δ_(A)=5.02, δ_(B)=5.19, J=12.6 Hz, 2H), 6.68 (s, 1H), 6.91-7.34 (m, 13H).

e. (+)-5-(Benzyloxycarbonyl)-1,6-dihydro-2-methoxy-4-ethyl-6-(3,4-diflurophenyl)pyrimidine. To a stirred solution of (+)-5-(benzyloxycarbonyl)-4-ethyl-1,6-dihydro-1-{N-[2-phenyl)ethyl]}carboxamido-2-methoxy-6-(3,4-diflurophenyl)pyrimidine (1.83 mmol, 1.0 g) in toluene (10 mL) was added 1,8-diazabicyclo[5,4,0]-undec-7-ene (0.81 mmol,0.12 mL) at room temperature and the resulting solution was heated to reflux for 5 h and then stirred for 12 h at room temperature. The solvent was evaporated and the residue was purified by flash column chromatography on silica gel with 3:1 EtOAc/Hexanes as the eluting system. 0.56 g of the (+)-5-(benzyloxycarbonyl)-1,6-dihydro-2-methoxy-4-ethyl-6-(3,4-diflurophenyl)pyrimidine was obtained (77%).

f. (+)-5-(Benzyloxycarbonyl)-4-ethyl-1,6-dihydro-2-methoxy-6-(3,4-diflurophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine. To a well stirred solution of (+)-5-(benzyloxycarbonyl)-1,6-dihydro-2-methoxy-4-ethyl-6-(3,4-diflurophenyl)pyrimidine (17.0 g, 44.04 mmol) and 4-dimethylaminopyridine (6.99 g, 57.25 mmol) in CH₂Cl₂ (200 mL) was added a powder of 4-nitrophenyl chloroformate 11.54 g, 57.25 mmol) at room temperature. The reaction mixture was stirred for 12 hours and then the solvent was removed in vacuo. The residue was purified by chromatography (SiO2, EtOAc/Hexane 10-30%) to get (+)-5-(benzyloxycarbonyl)-4-ethyl-1,6-dihydro-2-methoxy-6-(3,4-diflurophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine as a colorless viscous oil (19.3 g, 76%).

g. (+)-5-(Benzyloxycarbonyl)-6-(3,4-difluorophenyl)-4-ethyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-2-oxo-1,2,3,6-tetrhydropyrimidine. To a stirred mixture of (+)-5-(benzyloxycarbonyl)-4-ethyl-1,6-dihydro-2-methoxy-6-(3,4-difluorophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine (0.55 g, 1.12 mmol) in THF (5 mL) was added a solution of 3-[4-methoxycarbonyl-4-phenylpiperidin-1-yl]propylamine (0.31 g, 1.12 mmol) in THF (5 mL) at room temperature. The stirring was continued for 12 hours. A solution of 10% HCl in water (2 mL) was added and stirred for 2 h. The solvent was then removed in vacuo and the residue was extracted with ethyl acetate (3×10 mL). It was washed with 10% aq. KOH solution, dried over Na₂SO₄ and solvent was removed in vacuo to obtain (+)-5-(benzyloxycarbonyl)-6-(3,4-difluorophenyl)-4-ethyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-2-oxo-1,2,3,6-tetrhydropyrimidine as a white foamy compound (0.73 g, 96.6%) the purity of which was characterized as its HCl salt. It was used in the next step without further purification. Anal. Calcd. for C₃₇H₄₁ClF₂N₄O₆. 0.5 CHCl₃: C, 58.43; H, 5.43; N, 7.27. Found: C, 58.11, H; 5.85; N, 7.64.

h. 6-(3,4-Difluorophenyl)-4-ethyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-1,2,3,6-tetrhydro-2-oxopyrimidine-5-carboxylic acid. To a suspension of 10% Pd—C (0.14 g, 20% by wt.) in MeOH (3 mL) was added the solution of (+)-5-(benzyloxycarbonyl)-6-(3,4-difluorophenyl)-4-ethyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-2-oxo-1,2,3,6-tetrhydropyrimidine at room temperature with constant stirring. A balloon filled with H₂ was attached and the reaction mixture was stirred for 48 hours. The black suspension was filtered through a pad of celite and the filtrate was concentrated in vacuo. The residue was purified by column chromatography (SiO₂, 10% MeOH in EtOAc) to obtain (+)-6-(3,4-difluorophenyl)-4-ethyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-1,2,3,6-tetrhydro-2-oxopyrimidine-5-carboxylic acid as a white solid. M.P. 184-186° C.; [α]_(D)=+142.2 (c=0.25, CHCl₃) The purity was checked by combustion analysis as a HC₁ salt. Anal. Calcd. for C₃₀H₃₅ClF₂N₄O₆. 0.3 CHCl₃: C, 55.40; H, 5.42; N, 8.53. Found: C, 55.34; H; 5.80; N, 8.13.

(+)-5-Carboxamido-6-(3,4-difluorophenyl)-4-ethyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-2-oxo-1,2,3,6-tetrhydropyrimidine. To a solution of (+)-6-(3,4-difluorophenyl)-4-ethyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-1,2,3,6-tetrhydro-2-oxopyrimidine-5-carboxylic acid (0.22 g, 0.375 mmol) in CH₂Cl₂ (3 mL) was added 4-N,N-dimethylamino pyridine (0.14 g, 1.12 mmol) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.21 g, 1.12 mmol) under argon and the resulting solution was stirred at room temperature for 2 h. Three drops of saturated NH₄OH was then added and the solution was stirred for 48 h. The solution was washed with water (5 ml) and dried over Na₂SO₄. The solvent was removed in vacuo and the residue was purified by column chromatography (SiO₂, 10% MeOH in CHCl₃) to obtain 5-carboxamido-6-(3,4-difluorophenyl)-4-ethyl-1-{N-[3-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)propyl]}carboxamido-2-oxo-1,2,3,6-tetrhydropyrimidine as a beige solid (0.1 g, 45%) Characterized as HCl salt. M.P. 136-138° C., [α]_(D)=+111.44 (c=0.18, MeOH): δ 1.21 (t, J=7.5 Hz, 3H), 1.60-1.75 (m, 2H), 1.92-2.1 (m, 8H), 2.33 (t, J=6.6 Hz, 2H), 2.44-2.52 (m, 2H), 2.53-2.84 (m, 4H), 3.27-3.32 (m, 2H), 3.60 (s, 3H), 5.60 (br s,2H), 6.47 (s, 1H), 7.05-7.33 (m, 8H), 8.80 (br t, 1H), Anal. Calcd. for C₃₀H₃₅ClF₂N₄O₆. 1.0 CHCl₃: C, 50.35; H, 5.04; N, 9.47. Found: C, 50.40; H; 5.33; N, 9.13.

Example 21

6-(3,4-Difluorophenyl)-5-methoxycarbonyl-4-methyl-2-oxo-1-{N-[4-(2-pyridyl)-piperidine-1-yl]propyl}carboxamido-1,2,3,6-tetrahydropyrimidine dihydrochloride (Scheme 7).

a. 1-Benzyl-4-cyano-4-(2-pyridyl)piperidine. To a mixture of N,N-bis-(2-chloroethyl)benzylamine (E. Szarvasi, Eur. J. Med. Chem. Chim. Ther. 11(2), 115-124, 1976) (60 g, 22 mmol), 2-pyridylacetonitrile (2.51 ml, 22 mmol) and tetrabutylammonium hydrogen sulfate (0.26 g, 0.7 mmol) in toluene (10 ml), sodium hydroxide solution (2.43 g in 4.86 ml H₂O) was added over a 20 minute period. The reaction mixture was heated at 65° C. for 4 hours. The reaction mixture was cooled to room temperature, 10 ml of water was added and the solution partitioned between ethyl acetate (45 ml) and water. The organic layer was dried over sodium sulfate, filtered and concentrated. Purification of the crude product by column chromatography (hexane:EtOAc,2:3) gave 6.2 g (87%) of the title compound as a red solid; ¹H-NMR (CDCl₃): δ 2.05 (d, J=13.1 Hz, 2 H), 2.30 (t, J=13.2 Hz, 2 H), 2.48 (t, J=13.2 Hz, 2 H), 2.97 (d, J=12.1 Hz, 2 H), 3.57 (s, 2 H), 7.19-7.27 (m, 6 H), 7.30 (d, J=7.6 Hz, 1 H), 7.60 (t, J=7.6 Hz, 1 H), 8.58 (d, J=4.6 Hz,1H).

b. 1-Benzyl-4-carboxamido-4-(2-pyridyl)piperidine. To 1-benzyl-4-cyano-4-(2-pyridyl)piperidine (4.5 g, 14.3 mmol), 10 ml of conc.H₂SO₄ was added and the solution was stirred at room temperature for 24 hours. It was cooled to 0° C., diluted with ice pieces and poured into crushed ice. The mixture was then carefully neutralized with 50% NaOH solution. The reaction mixture was repeatedly extracted with chloroform (3×25 ml), dried over sodium sulfate, filtered and concentrated to give 4.5 g (95%) of the crude product which was used as such for the subsequent step; ¹H-NMR (CDCl): δ 2.21-2.28 (m, 2 H), 2.47 (s, 6 H), 3.41 (s, 2 H), 5.23 (s, 1 H), 6.40 (s, 1 H), 7.12-7.29 (m, 6 H), 7.33 (d, J=7.6 Hz, 1 H), 7.63 (t, J=7.6 Hz, 1 H), 8.55 (d, J=4.6 Hz, 1 H).

c. 1-Benzyl-4-(2-pyridyl)-piperidine. To 1-benzyl-4-carboxamido-4-(2-pyridyl)piperidine (4.5 g, 13.5 mmol) in anhydrous methanol (100 ml), HCl gas was bubbled through the solution at 0° C. for 15 minutes. The reaction mixture was then refluxed for 24 hours. It was cooled to room temperature, concentrated, neutralized with 50% NaOH and repeatedly extracted with chloroform (3×25 ml). The combined organic layer was then dried over sodium sulfate, filtered and concentrated. Flash chromatography (hexane:ethylacetate, 1:4) of the crude product yielded 1.72 g (50%) of the product as a syrup; ¹H-NMR (CDCl₃): δ 1.8-1.94 (m, 4 H), 2.11 (t, J=11.4 Hz, 2 H), 2.70-2.72 (m, 1 H), 3.02 (d, J=11.4 Hz, 2 H), 3.54 (s, 2 H), 7.07-7.36 (m, 7 H), 7.58 (t, J=7.6 Hz, 1 H), 8.52 (d, J=4.6 Hz, 1 H).

d. 3-[4-(2-Pyridyl)-piperidine-1-yl]propylamine (Scheme 6). To 1-Benzyl-4-(2-pyridyl)-piperidine (3.26 g, 12.9 mmol) in dry methanol (25 ml), 10% palladium hydroxide (1.9 g) was added and the solution was hydrogenated at 200 psi for 24 hours. The solution was filtered over celite, concentrated to give 2.1 g (99%) of 4-(2-pyridyl)-piperidine which was used as such for the subsequent step. A mixture of 3-bromopropylamine hydrobromide (20 g, 91.3 mmol), potassium carbonate (37.85 g, 273.9 mmol) and di-tert-butyldicarbonate (21.90 g, 100 mmol) in methanol was stirred at room temperature for 24 hours. The reaction mixture was concentrated and partitioned between 250 ml EtOAc and 50 ml water, dried over sodium sulfate, filtered and concentrated. Purification of the crude product by column cromatography (Hexane: EtOAc, 4.5:0.5) gave 17.5 g (80%) of the product as a pale yellow oil. To a stirred solution of the 4-(2-pyridyl)-piperidine (1.86 g, 11.4 mmol) in dioxane (20 ml), N-(tert-butoxycarbonyl)-3-bromopropylamine (2.82 g, 11.4 mmol) and potassium carbonate (3.16 g, 22.9 mmol) were added and the solution refluxed for 24 hours. The reaction mixture was cooled to room temperature, concentrated and partitioned between 40 ml chloroform and 5 ml water. The organic layer was dried over sodium sulfate, filtered and concentrated. The crude product was purified by column chromatography (ethyl acetate: methanol, 4:1) to yield 1.86 g (49%) of the required product as a colorless oil; ¹H-NMR (CDCl₃): δ 1.45 (s, 9 H), 1.54-1.69 (m, 8 H), 2.21-2.68 (m, 2 H), 2.74-2.80 (m, 1 H), 3.02-3.22 (m, 4 H), 5.41 (s, 1H), 7.13-7.17 (m, 1 H), 7.33 (d, J=7.93 Hz, 1 H), 7.63 (t, J=7.6 Hz, 1 H), 8.54 (d, J=4.6 Hz, 1 H). To N-(tert-butoxycarbonyl)-3-[4-(2-pyridyl)-piperidin-1-yl]propylamine (0.15 g, 0.45 mmol) in 5 ml of dichloromethane, 1 ml of trifluoroacetic acid was added and the solution stirred at room temperature for 1 hour. The solution was concentrated, neutralized with 10% KOH solution and extracted into 25 ml of dichloromethane. The organic layer was dried over sodium sulfate, filtered and concentrated to give 0.098 g (100%) of 3-[4-(2-pyridyl)-piperidin-1-yl]propylamine which was used as such for the subsequent step (step h).

e. Methyl 2-{(3,4-difluorophenyl)methylene}-3-oxobutyrate. A mixture of 3,4-difluorobenzaldehyde (14.2 g, 0.1 mol), methyl acetoacetate (12.2 g, 0.105 mol), piperidine (0.430 g, 5 mmol), and acetic acid (0.30 g, 5 mmol) in benzene (150 mL) was stirred and refluxed with a Dean-Stark trap for 8 hours. Benzene was evaporated, the residue was dissolved in ethyl acetate (200 mL) and washed with brine (50 mL), saturated potassium bisulfate solution (50 mL), and saturated sodium bicarbonate solution in sequence. The ethyl acetate solution was dried (magnesium sulfate), solvent removed under reduced pressure and the residue was purified by column chromatography (SiO2, EtOAc/hexane, 10%-15%). The product, methyl 2-{(3,4-difluorophenyl)methylene}-3-oxobutyrate, was obtained as a yellow oil (0.98 g, 98.3%) and was used in the next step without any further characterization.

f. 6-(3,4-Difluorophenyl)-1,6-dihydro-2-methoxy-5-methoxycarbonyl-4-methylpyrimidine. A mixture of methyl 2-{(3,4-difluorophenyl)methylene}-3-oxobutyrate (8.8 g, 36.6 mmol), O-methylisourea hydrogen sulfate (9.4 g, 55 mmol), and NaHCO₃ (12.3 g, 0.146 mol) in DMF (30 mL) was stirred and heated at 70° C. for 16 hours. The mixture was cooled, diluted with EtOAc (300 mL) and washed with water (5×300 mL), brine (300 mL), and dried (MgSO₄). Solvent was evaporated and the crude product was purified by flash column chromatography on silica gel using 10% through 20% EtOAc in hexane as the gradient eluent, to leave the product as an oil (3.82 g, 30.2%); ¹H-NMR (CDCl₃): δ 2.32,2.39 (2 s, 3 H), 3.58, 3.64 (2 s, 3 H), 3.72, 3.85 (2 s, 3 H), 5.55 (s, 1 H), 6.13-7.8 (m, 4 H).

g. 6-(3,4-Difluorophenyl)-1,6-dihydro-2-methoxy-5-methoxycarbonyl-4-methyl-1-[(4-nitrophenyloxy)carbonyl]pyrimidine. To a solution of 6-(3,4-difluorophenyl)-1,6-dihydro-2-methoxy-5-methoxycarbonyl-4-methylpyrimidine (2.82 g, 9.52 mmol) and 4-dimethylaminopyridine (1.16 g, 9.52 mmol) in CH₂Cl₂ (50 mL), at 0-5° C., 4-nitrophenyl chloroformate (1.82 g, 9.04 mmcl) was added and the mixture was allowed to warm to room temperature. After 12 hours solvent was evaporated and the residue was purified by flash column chromatography (SiO₂, EtOAc/hexane, 10%-15%) to obtain the product as white crystals (3.72, 84.7%); m.p. 172-174° C.; ¹H-NMR (CDCl₃): δ 2.51 (s, 3 H), 3.72 (s, 3 H), 3.97 (s, 3 H), 6.26 (s, 1 H), 7.0-7.3 (m, 3 H), 7.38 (d, J=9.3 Hz, 2 H), 8.32 (d, J=9.3 Hz, 2 H).

h. 6-(3,4-Difluorophenyl)-5-methoxycarbonyl-4-methyl-2-oxo-1-{N-[4-(2-pyridyl)-piperidine-1-yl]propyl}carboxamido-1,2,3,6-tetrahydropyrimidine dihydrochloride. To 6-(3,4-difluorophenyl)-1,6-dihydro-2-methoxy-5-methoxycarbonyl-4-methyl-1-(4-nitrophenoxy)carbonylpyrimidine (0.04 g,0.086 mmol) in 10 ml of dry dichloromethane, 3-[4-(2-pyridyl)-piperidine-1-yl]propylamine (0.038 g, 0.17 mmol) was added and the solution was stirred at room temperature for 24 hours. The reaction mixture was stirred for another 1 hour after addition of 2 ml of 6N HCl. After neutralization with 10% aqueous KOH solution, the reaction mixture was extracted into dichloromethane (3×10 ml). The organic layer was dried over sodium sulfate, filtered and concentrated. The crude product was purified by flash chromatography (EtOAc: MeOH, 4.5:0.5) to give 0.040 g (89%) as a syrup; ¹H-NMR (CDCl₃): δ 1.73-2.11 (m, 7 H), 2.41 (s, 6 H), 2.69 (m, 1 H), 3.04 (d, J=12.1 Hz, 2 H), 3.31-3.48 (m, 2 H), 3.71 (s, 3 H), 6.70 (s, 1 H), 7.24-7.27 (m, 5 H), 7.61 (t, J=8.0 Hz, 2 H), 8.51 (d, J=4.6 Hz, 1 H), 8.89 (t, J=5.1 Hz, 2 H).

To the free base (0.04 g, 0.07 mmol) in 4 ml of dichloromethane, 5 ml of 1N HCl in ether was added, and the solution concentrated under reduced pressure. Recrystallization from ether gave 0.046 g (98%) of 6-(3,4-difluorophenyl)-5-methoxycarbonyl-4-methyl-2-oxo-1-{N-[4-(2-pyridyl)-piperidine-1-yl]propyl}carboxamido-1,2,3,6-tetrahydropyrimidine dihydrochloride as a white solid; m.p. 170-174° C.; Anal. Calcd. for C₂₇H₃₃Cl₂F₂N₅O₄. 1.0 H₂O: C, 52.43; H,5.70, N, 11.30. Found: C, 52.16; H, 5.35; N, 11.10.

Example 22

6-(3,4-Benzofurazan-5-yl)-5-methoxycarbonyl-4-methyl-2-oxo-1-{N-[4-(2-pyridyl)-piperidin-1-yl]propyl}carboxamido-1,2,3,6-tetrahydropyrimidine dihydrochloride (Scheme 8).

5-Methylbenzfuroxan. 4-Methyl-2-nitroaniline (100 g, 0.650 mol) was suspended in saturated alcoholic sodium hydroxide solution (1.50 l). To this suspension was added with cooling (5° C.) commercial aqueous sodium hypochlorite till the red color disappeared. The fluffy yellow precipitate formed was filtered, washed with cold water and recrystallized from ethanol to get 5-Methylbenzfuroxan (88.2 g, 89% yield) as a pale solid.

5-Methylbenzofurazan. To 5-Methylbenzfuroxan (88.2 g, 0.59. mol) in refluxing EtOH (75 ml) was added dropwise P(OEt)₃ (150 ml). When addition was complete, refluxing was continued for 1 more hour. The solvent was removed by rotary evaporation and the residue shaken with water (200 mL) and allowed to stand overnight at (0˜5° C.). The brown solid so obtained was filtered, washed with water and chromatograghed on silica gel to yield 5-Methylbenzofurazan (70 g, 87%) as white needle.

5-Dibromomethylbenzofurazan. 5-Methylbenzofurazan (70 g, 0.52 mol), NBS (325 g), and benzoyl peroxide (0.5 g) were refluxed with stirring in carbon tetrachloride (1.5 L) with exclusion of moisture for 30 hours. The reaction mixture was washed with water (2×0.5L), dried (NaSO₄), and the solvent was removed in vacuo. The residue was chromatographed (silica, EtOAc-hexane, 1:150) to give 122 g (80%) of the title compound. The resulting white solid was used in the next step without any further characterization.

5-Formylbenzofurazan. To a refluxing mixture of the dibromomethylbenzofurazan (122 g, 418 mmol) in EtOH (1 L) was added AgNO₃ (163 g) in 2 L of water. Refluxing was continued for 2 hours. The mixture was cooled and the AgBr was removed by filtration through Celite, and the solvent was concentrated to a small volume. The resulting solution was extracted with toluene (10×100 mL), dried (MgSO₄), and the solvent was removed in vacuo. The residue was chromatographed on silica (EtOAc-hexane, 8:1000) to give 48.2 g of the title aldehyde (78%) as a white solid.

a. Methyl 2-{(benzofuran-5-yl)methylene}-3-oxobutyrate. A mixture of 5-Formylbenzofurazan (0.6 g, 4.1 mmol), methyl acetoacetate (0.52 g, 4.5 mmol), piperidine (0.019 g, 0.225 mmol), and acetic acid (0.014 g, 0.225 mmol) In benzene (30 mL) was stirred and refluxed with a Dean-Stark trap for 8 h. Benzene was evaporated, the residue was dissolved in ethyl acetate (80 mL) and washed with brine (50 mL), saturated potassium bisulfate solution (50 mL), and saturated sodium bicarbonate solution in sequence. The ethyl acetate solution was dried (magnesium sulfate), solvent removed under reduced pressure and the residue was purified by column chromatography (SiO2, EtOAc/hexane, 10%-15%). The product, methyl 2-{(benzofuran-5-yl)methylene}-3-oxobutyrate, was obtained as an oil (0.98 g, 98.3%) and was used in the next step without any further characterization.

b. 6-(Benzofurazan-5-yl)-1,6-dihydro-2-methoxy-5-methoxycarbonyl-4-methylpyrimidine. A mixture of methyl2-{(benzofuran-5-yl)methylene}-3-oxobutyrate (1.02 g, 4.1 mmol), O-methylisourea hydrogen sulfate (1.06 g, 6.2 mmol), and NaHCO₃ (1.3 g, 16.4 mmol) in DMF (15 mL) was stirred and heated at 70° C. for 16 h. The mixture was cooled, diluted with EtOAc (50 mL) and washed with water (5×50 mL), brine (50 mL), and dried (MgSO₄). Solvent was evaporated and the crude product was purified by flash column chromatography on silica gel using 10% through 20% EtOAc in hexane as the gradient eluent, to leave the product as an oil (0.52 g, 43%); ¹H-NMR (CDCl₃): δ 2.38,2.42 (2 s, 3 H), 3.60, 3.66 (2 s, 3 H), 3.74, 3.82 (2 s, 3 H), 5.53, 5.68 (2 s, 1 H), 6.31, 6.32 (br s, 1 H), 7.0-7.8 (m, 3 H).

c. 6-(Benzofurazan-5-yl)-1,6-dihydro-2-methoxy-5-methoxycarbonyl-4-methyl-1-[(4-nitrophenyloxy)carbonyl]pyrimidine. To a solution of 6-(benzofuran-5-yl)-1,6-dihydro-2-methoxy-5-methoxycarbonyl-4-methylpyrimidine (0.485 g, 1.6 mmol) and 4-dimethylaminopyridine (0.2 g, 1.6 mmol) in CH₂Cl₂ (20 mL), at 0-5° C., was added 4-nitrophenyl chloroformate (0.307 g, 1.52 mmol) and the mixture was allowed to warm to room temperature. After 12 hours solvent was evaporated and the residue was purified by flash column chromatography (SiO2, EtOAc/hexane, 10%-15%) to obtain the product as white crystals (0.665 g, 89%); m.p. 180-183° C.; ¹H-NMR (CDCl₃): δ 2.54 (s, 3 H), 3.75 (s, 3 H), 3.98 (s, 3 H), 6.37 (s, 1 H), 7.40 (d, J=9.3 Hz, 2 H), 7.52 (d, J=9.0 Hz, 1 H), 7.68 (s, 1 H), 7.84 (d, J=9.0 Hz, 1 H), 8.32 (d, J=9.3 Hz, 2 H).

d. 6-(3,4-Benzofurazan-5-yl)-5-methoxycarbonyl-4-methyl-2-oxo-1-{N-[4-(2-pyridyl)-piperidin-1-yl]propyl}carboxamido-1,2,3,6-tetrahydropyrimidine dihydrochloride. To 6-(benzofurazan-5-yl)-1,6-dihydro-2-methoxy-5-methoxycarbonyl-4-methyl-1-(4-nitrophenoxy)carbonylpyrimidine (0.04 g,0.085 mmol) in 10 ml of dry dichloromethane, 3-[4-(2-pyridyl)-piperidine-1-yl]propylamine (0.037 g, 0.17 mmol) was added and the solution was stirred at room temperature for 24 hours. The reaction mixture was stirred for another 1 hour after addition of 2 ml of 6N HCl. After neutralization with 10% aqueous KOH solution, the reaction mixture was extracted into dichloromethane (3×10 ml). The organic layer was dried over sodium sulfate, filtered and concentrated. The crude product was purified by flash chromatography (EtOAc: MeOH, 4.5:0.5) to give 0.040 g (89%) as a syrup; ¹H-NMR (CDCl₃): δ 1.74-2.10 (m, 7 H), 2.46 (s, 6 H), 2.70-2.72 (m, 1 H), 3.05 (d, J=12.1 Hz, 2 H), 3.34-3.48 (m, 2 H), 3.76 (s, 3 H), 6.82 (s, 1 H), 7.11-7.32 (m, 3 H), 7.54-7.78 (m, 4 H), 8.53 (d, J=4.6 Hz, 1 H), 8.89 (t, J=5.16 Hz, 2 H).

To the free base (0.04 g, 0.07 mmol) in 4 ml of dichloromethane, 5 ml of 1N HCl in ether was added, and the solution concentrated under reduced pressure. Recrystallization from ether gave 0.040 g (87%) of 6-(3,4-benzofurazan-5-yl)-5-methoxycarbonyl-4-methyl-2-oxo-1-{N-[4-(2-pyridyl)-piperidine-1-yl]propyl}carboxamido-1,2,3,6-tetrahydropyrimidine dihydrochloride as a white solid; m.p. 200-204° C.; Anal. Calcd. for C₂₇H₃₃Cl₂N₇O₅. 2.5 H₂O: C, 49.77; H,5.88. Found: C, 49.41; H, 5.20.

Example 23

6-(3,4-Difluorophenyl)-1,6-dihydro-5-methoxycarbonyl-1-(5-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)-pentyl)-2,4-dimethylpyrimidine (Scheme 9).

a. 6-(3,4-Difluorophenyl)-1,6-dihydro-2,4-dimethyl-5-methoxycarbonylpyrimidine. To a solution of acetamidine hydrochloride (1.53 g, 16.2 mmol.) in DMF (10 mL) were added a solution of potassium tert-butoxide (1.33 g, 11.8 mmol.) in DMF (10 mL) and a solution of methyl {2-(3,4-difluorophenyl)methylene}-3-oxobutanoate (2.6 g, 10.8 mmol.) in DMF (10 mL) at 0° C. After the mixture was stirred for 0.5 hour at 0° C., p-toluenesulfonic acid monohydrate (4.1 g, 21.5 mmol.) was added. The mixture was heated at 100-120° C. for 2 hrs. The reaction mixture was cooled to room temperature, quenched with aqueous NaOH solution (2N, 60 mL), and extracted with ether. The organic layer was dried over Na₂SO₄ and evaporated. The residue was flash chromatographed over silica gel (eluent: ethyl acetate) to give the product in 59% yield (1.8 g) as a yellow solid: ¹H NMR (300 MHz, CDCl₃) δ 1.98 (3H, s), 2.31 (3H, s), 3.59 (3H, s), 5.47 (1H, s), 7.03-7.05 (3H, m).

b. 1-(5-Chloropentyl)-6-(3,4-difluorophenyl)-1,6-dihydro-2,4-dimethyl-5-methoxycarbonylpyrimidine. To a suspension of NaH (90 mg, 60% dispersion in mineral oil, 2.25 mmol.) in THF (7 mL) was added a solution of the above yellow solid (0.6 g, 2.14 mmol.) in THF (8 mL, at 0° C. After 20 min, 1-bromo-5-chloropentane (1 mL, d 1.408, 7.59 mmol.) was added. The reaction mixture was then refluxed overnight. After the removal of the solvent, the residue was flash chromatographed over silica gel (eluent: ethyl acetate) to give the product in 75% yield (0.614 g) as a yellow oil: ¹H NMR (300 MHz, CDCl₃) δ 1.42-1.75 (6H, m), 2.17 (3H, s), 2.28 (3H, s), 3.05-3.45 (2H, m), 3.49 (2H, t, J=5.88 Hz), 3.63 (3H, s), 5.23 (1H, s), 7.01-7.15 (3H, m).

c. 6-(3,4-Difluorophenyl)-1,6-dihydro-5-methoxycarbonyl-1-(5-(4-methoxycarbonyl-4-phenylpiperidin-1-yl)-pentyl)-2,4-dimethylpyrimidine. A mixture of the above yellow oil (0.667 g, 1.73 mmol.), 4-methoxycarbonyl-4-phenylpiperidine (0.76 g, 3.47 mmol.), potassium carbonate (0.96 g, 6.95 mmol.), sodium iodide (0.52 g, 3.47 mmol.) and 1,4-dioxane (15 mL) was refluxed overnight. The undissolved solid was then filtered off and the solvent was evaporated. The residue was flash chromatographed over silica gel (eluent: 80:20 v/v ethyl acetaze-2M ammonia in methanol) to give the title compound in 78% yield (0.768 g) as a yellow oil: CIMS, m/z 568 (MH⁺); ¹H NMR (300 MHz, CDCl₃) δ 1.23-1.28 (2H, m), 1.43-1.51 (2H, m), 1.77-2.13 (8H, m), 2.16 (3H, s), 2.28 (3H, s), 2.47-2.55 (2H, m), 2.74-2.81 (2H, m), 3.00-3.12 (1H, m), 3.22-3.38 (1H, m), 3.613 (3H, s), 3.615 (3H, s), 5.22 (1H, s), 6.99-7.35 (3H, m).

Treatment of the free base with 2 equivalents of 1M HCl in ether gave the HCl salt as a yellow foam: m.p. 170-176° C. Anal. Calc. for C₃₂H₃₉F₂N₃O₄ 2HCl 2.3 H₂O: C, 56.35; H, 6.74; N, 6.16; Found: C, 56.34; H, 6.62; N, 5.86.

Pharmacological Profiles of the Compounds in Cloned Human Adrenergic Receptors.

Binding affinities were measured for selected compounds of the invention at six cloned human alpha-1 and alpha-2 receptor subtypes, as well as at the L-type calcium channel. The protocols for these experiments are given below.

Protocol for the Determination of the Potency of α₁ Antagonists

The activity of compounds at the different human receptors was determined in vitro using cultured cell lines that selectively express the receptor of interest. These cell lines were prepared by transfecting the cloned cDNA or cloned genomic DNA or constructs containing both genomic DNA and cDNA encoding the human α-adrenergic receptors as follows:

α_(1A) Human Adrenergic Receptor: The entire coding region of α1A (1719 bp), including 150 base pairs of 5′ untranslated sequence (5′ UT) and 300 bp of 3′ untranslated sequence (3′ UT), was cloned into the BamHI and ClaI sites of the polylinker-modified eukaryotic expression vector pCEXV-3, called EXJ.HR. The construct involved the ligation of partial overlapping human lymphocyte genomic and hippocampal cDNA clones: 5′ sequence were contained on a 1.2 kb SmaI-XhoI genomic fragment (the vector-derived BamHI site was used for subcloning instead of the internal insert-derived SmaI site) and 3′ sequences were contained on an 1.3 kb XhoI-ClaI cDNA fragment (the ClaI site was from the vector polylinker). Stable cell lines were obtained by cotransfection with the plasmid α1A/EXJ (expression vector containing the α1A receptor gene) and the plasmid pGCcos3neo (plasmid containing the aminoglycoside transferase gene) into LM(tk⁻), CHO, and NIH3T3 cells, using calcium phosphate technique. The cells were grown, in a controlled environment (37° C., 56% CO₂), as monolayers in Dulbecco's modified Eagle's Medium (GIBCO, Grand Island, N.Y.) containing 25 mM glucose and supplemented with 10% bovine calf serum, 100 units/ml penicillin g, and 100 μg/ml streptomycin sulfate. Stable clones were then selected for resistance to the antibiotic G-418 (1 mg/ml), and membranes were harvested and assayed for their ability to bind [³H]prazosin as described below (see “Radioligand Binding assays”).

α_(1B) Human Adrenergic Receptor: The entire coding region of α1B (1563 bp), including 200 base pairs and 5′ untranslated sequence (5′ UT) and 600 bp of 3′ untranslated sequence (3′ UT), was cloned into the EcoRI site of pCEXV-3 eukaryotic expression vector. The construct involved ligating the full-length containing EcoRI brainstem cDNA fragment from λ ZapII into the expression vector. Stable cell lines were selected as described above.

α_(1C) Human Adrenergic Receptor: The entire coding region of α1C (1401 bp), including 400 base pairs of 5′ untranslated sequence (5′ UT) and 200 bp of 3′ untranslated sequence (3′ UT), was cloned into the KpnI site of the polylinker-modified pCEXV-3-derived eukaryotic expression vector, EXJ.RH. The construct involved ligating three partial overlapping fragments: a 5′ 0.6 kb HincII genomic clone, a central 1.8 EcoRI hippocampal cDNA clone, and a 3′ 0.6 Kb PstI genomic clone. The hippocampal cDNA fragment overlaps with the 5′ and 3′ genomic clones so that the HincII and PstI sites at the 5′ and 3′ ends of the cDNA clone, respectively, were utilized for ligation. This full-length clone was cloned into the KpnI site of the expression vector, using the 5′ and 3′ KpnI sites of the fragment, derived from vector (i.e., pBluescript) and 3′-untranslated sequences, respectively. Stable cell lines were selected as described above.

Radioligand Binding Assays: Transfected cells from culture flasks were scraped into 5 ml of 5 mM Tris-HCl, 5 mM EDTA, pH 7.5, and lysed by sonication. The cell lysates were centrifuged at 1000 rpm for 5 min at 4° C., and the supernatant was centrifuged at 30,000×g for 20 min at 4° C. The pellet was suspended in 50 mM Tris-HCl, 1 mM MgCl₂, and 0.1% ascorbic acid at pH 7.5. Binding of the α1 antagonist [³H]prazosin (0.5 nM, specific activity 76.2 Ci/mmol) to membrane preparations of LM(tk-) cells was done in a final volume of 0.25 ml and incubated at 37° C. for 20 min. Nonspecific binding was determined in the presence of 10 μM phentolamine. The reaction was stopped by filtration through GF/B filters using a cell harvester. Inhibition experiments, routinely consisting of 7 concentrations of the tested compounds, were analyzed using a non-linear regression curve-fitting computer program to obtain Ki values.

α₂ Human Adrenergic Receptors: To determine the potency of α₁ antagonists at the U2 receptors, LM(tk-) cell lines stably transfected with the genes encoding the α_(2A), α_(2B), and α_(2C), receptors were used. The cell line expressing the α_(2A) receptor is designated L-α_(2A), and was deposited on Nov. 6, 1992 under ATCC Accession No. CRL 11180. The cell line expressing the α_(2B) receptor is designated L-NGC-α_(2B), and was deposited on Oct. 25, 1989 under ATCC Accession No. CRL10275. The cell line expressing the α_(2C) receptor is designated L-α_(2C), and was deposited on Nov. 6, 1992 under ATCC Accession No. CRL-11181. Cell lysates were prepared as described above (see Radiollgand Binding Assays), and suspended in 25 mM glycylglycine buffer (pH 7.6 at room temperature). Equilibrium competition binding assay were performed using [3H]rauwolscine (0.5 nM), and nonspecific binding was determined by incubation with 10 μM phentolamine. The bound radioligand was separated by filtration through GF/B filters using a cell harvester.

Determination of the Activity of α₁ Antagonists at Calcium Channels

The potency of α₁ antagonists at calcium channels was determined in competition binding assays of [3H]nitrendipine to membrane fragments of rat cardiac muscle, essentially as described by Glossman and Ferry (Methods in Enzymology 109:513-550, 1985). Briefly, the tissue was minced and homogenized in 50 mM Tris-HCl (pH 7.4) containing 0.1 mM phenylmethylsulfonyl fluoride. The homogenates were centrifuged at 1000 g for 15 minutes, the resulting supernatant was centrifuged at 45,000 g for 15 minutes. The 45,000 g pellet was suspended in buffer and centrifuged a second time. Aliquots of membrane protein were incubated for 30 minutes at 37° C. in the presence of [3H]nitrendipine (1 nM), and nonspecific binding was determined in the presence of 10 μM nifedipine. The bound radioligand was separated by filtration through GF/B filters using a cell harvester.

The compounds described above were assayed using cloned human alpha adrenergic receptors and the rat calcium channel. The preferred compounds were found to be selective as antagonists. The binding affinities of compounds 19-23 are illustrated in the following table. Binding affinities of compounds 19-23 at cloned human α1a, α1b, and α1c receptors.

hα1a hα1b hα1c Example pKi SEM n pKi SEM n pKi SEM n 19 6.14 0.02 3 6.21 0.09 3 9.74 0.02 3 20 6.46 0.04 3 6.59 0.08 3 9.68 0.05 3 21 6.01 0.03 3 6.33 0.06 3 9.41 0.09 3 22 6.24 0.06 3 6.37 0.06 3 9.54 0.09 3 23 6.17 0.04 4 6.32 0.06 4 8.99 0.12 4 h = human 

What is claimed is:
 1. A method of treating a subject suffering from benign prostatic hyperplasia which comprises administering to the subject an amount of a compound effective to treat benign prostatic hyperplasia, wherein the compound has the structure:

wherein A is

wherein each of Y₁, Y₂ and Y₃ is independently H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocycloalkyl, polyfluorocycloalkyl or cycloalkenyl; —F, —Cl, —Br, —I, —NO₂, —N₃, —CN, —OR₆, —OCOR₆, —COR₆, —CONHR₆, —CON(R₆)₂, —COOR₆, —CF₃ or together constitute a methylenedioxy group; wherein X is S, O or NH; wherein R₁ is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocycloalkyl, polyfluorocycloalkyl or cycloalkenyl; —NHR₆, —N(R₆)₂ or —OR₆; wherein R₂ is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocycloalkyl, polyfluorocycloalkyl or cycloalkenyl; C₃-C₁₀ cycloalkyl-C₁-C₁₀-alkyl, cycloalkyl-C₁-C₁₀-monofluoroalkyl or cycloalkyl-C₁-C₁₀-polyfluoroalkyl; —CN, —CH₂XR₆, —CH₂X(CH₂)_(n)NHR₆, —(CH₂)_(n)NHR₆, —CH₂X(CH₂)_(n)N(R₆)₂, —CH₂X(CH₂)_(n)N₃ or CH₂X(CH₂)_(n)NHCXR₇; wherein n is an integer from 0 to 5 and wherein X is as defined above; wherein R₃ is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocycloalkyl, polyfluorocycloalkyl or cycloalkenyl; wherein R₄ is

wherein each R is independently H; F; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; wherein R₅ is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocycloalkyl, polyfluorocycloalkyl or cycloalkenyl; phenyl, thiophenyl, pyridyl, pyrrolyl, furanyl, imidazolyl or indolyl; —COOR₆, —COR₆, —CONHR₆, —CN, —OH or —OR₆; wherein each m is independently an integer from 0 to 3; wherein o is an integer from 1 to 3; wherein each n is independently an integer from 0 to 5; wherein each R₆ is independently H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocycloalkyl, polyfluorocycloalkyl or cycloalkenyl; wherein R₇ is phenyl, pyridyl, thiophenyl, furanyl, pyrazinyl, pyrrolyl, naphthyl, indolyl, imidazolyl, benzfurazanyl, benzfuranyl or benzimidazolyl; C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl wherein the alkyl, monofluoroalkyl, polyfluoroalkyl, alkenyl or alkynyl is substituted with phenyl, pyridyl, thiophenyl, furanyl, pyrazinyl, pyrrolyl, naphthyl, indolyl, imidazolyl, benzfurazanyl, benzfuranyl or benzimidazolyl; wherein each of Y₁, Y₂ and Y₃ is as defined above; wherein X is as defined above; wherein Z is C₂ alkenyl or alkynyl, CH₂, O, CO, CO₂, CONR₆, S, SO, SO₂ or NR₆; and wherein each D is independently CH₂, O, S, NR₆, CO or CS; or a pharmaceutically acceptable salt thereof.
 2. A method of treating a subject suffering from a condition wherein the condition is selected from the group consisting of high intraocular pressure, impotency, and sympathetically mediated pain which comprises administering to the subject an amount of a compound effective to treat the condition wherein the compound has the structure:

wherein A is

wherein each of Y₁, Y₂ and Y₃ is independently H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocycloalkyl, polyfluorocycloalkyl or cycloalkenyl; —F, —Cl, —Br, —I, —NO₂, —N₃, —CN, —OR₆, —OCOR₆, —COR₆, —CONHR₆, —CON(R₆)₂, —COOR₆, —CF₃ or together constitute a methylenedioxy group; wherein X is S, O or NH; wherein R₁ is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocycloalkyl, polyfluorocycloalkyl or cycloalkenyl; —NHR₆, —N(R₆)₂ or —OR₆; wherein R₂ is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocycloalkyl, polyfluorocycloalkyl or cycloalkenyl; C₃-C₁₀ cycloalkyl-C₁-C₁₀-alkyl, cycloalkyl-C₁-C₁₀-monofluoroalkyl or cycloalkyl-C₁-C₁₀-polyfluoroalkyl; —CN, —CH₂XR₆, —CH₂X(CH₂)_(n)NHR₆, —(CH₂)_(n)NHR₆, —CH₂X(CH₂)_(n)N(R₆)₂, —CH₂X(CH₂)_(n)N₃ or CH₂X(CH₂)_(n)NHCXR₇; wherein n is an integer from 0 to 5 and wherein X is as defined above; wherein R₃ is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocycloalkyl, polyfluorocycloalkyl or cycloalkenyl; wherein R₄ is

wherein each R is independently H; F; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; wherein R₅ is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocycloalkyl, polyfluorocycloalkyl or cycloalkenyl; phenyl, thiophenyl, pyridyl, pyrrolyl, furanyl, imidazolyl or indolyl; —COOR₆, —COR₆, —CONHR₆, —CN, —OH or —OR₆; wherein each m is independently an integer from 0 to 3; wherein o is an integer from 1 to 3; wherein each n is independently an integer from 0 to 5; wherein each R₆ is independently H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocycloalkyl, polyfluorocycloalkyl or cycloalkenyl; wherein R₇ is phenyl, pyridyl, thiophenyl, furanyl, pyrazinyl, pyrrolyl, naphthyl, indolyl, imidazolyl, benzfurazanyl, benzfuranyl or benzimidazolyl; C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl wherein the alkyl, monofluoroalkyl, polyfluoroalkyl, alkenyl or alkynyl is substituted with phenyl, pyridyl, thiophenyl, furanyl, pyrazinyl, pyrrolyl, naphthyl, indolyl, imidazolyl, benzfurazanyl, benzfuranyl or benzimidazolyl; wherein each of Y₁, Y₂ and Y₃ is as defined above; wherein X is as defined above; wherein Z is C₂ alkenyl or alkynyl, CH₂, O, CO, CO₂, CONR₆, S, SO, SO₂ or NR₆; and wherein each D is independently CH₂, O, S, NR₆, CO or CS; or a pharmaceutically acceptable salt thereof.
 3. A method of treating a subject suffering from a condition wherein the condition is selected from the group consisting of a disorder associated with high cholesterol, a disease which is susceptible to treatment by antagonism of the α_(1C) receptor, and cardiac arrhythmia, which comprises administering to the subject an amount of a compound effective to treat the condition wherein the compound has the structure:

wherein A is

wherein each of Y₁, Y₂ and Y₃ is independently H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocycloalkyl, polyfluorocycloalkyl or cycloalkenyl; —F, —Cl, —Br, —I, —NO₂, —N₃, —CN, —OR₆, —OCOR₆, —COR₆, —CONHR₆, —CON(R₆)₂, —COOR₆, —CF3 or together constitute a methylenedioxy group; wherein X is S, O or NH; wherein R₁ is H; straight chained or branched C₁-C₇ alkyl, mnonofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocycloalkyl, polyfluorocycloalkyl or cycloalkenyl; or —NHR₆, —N(R₆)₂ or —OR₆; wherein R₂ is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocycloalkyl, polyfluorocycloalkyl or cycloalkenyl; C₃-C₁₀ cycloalkyl-C₁-C₁₀-alkyl, cycloalkyl-C₁-C₁₀-monofluoroalkyl or cycloalkyl-C₁-C₁₀-polyfluoroalkyl; or —CN, —CH₂XR₆, —CH₂X(CH₂)_(n)NHR₆, —(CH₂)_(n)NHR₆, —CH₂X(CH₂)_(n)N(R₆)₂, —CH₂X(CH₂)_(n)N₃ or CH₂X(CH₂)_(n)NHCXR₇; wherein n is an integer from 0 to 5 and wherein X is as defined above; wherein R₃ is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; or C₃-C₇ cycloalkyl, monofluorocycloalkyl, polyfluorocycloalkyl or cycloalkenyl; wherein R₄ is

with the proviso that when the compound has formula (a) and R₄ is (i), (iv), (viii) or (ix), R₇ is pyridyl, thiophenyl, furanyl, pyrazinyl, pyrrolyl, naphthyl, indolyl, imidazolyl, benzfurazanyl, benzfuranyl or benzimidazolyl; wherein each R is independently H; F; or straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; wherein R₅ is H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; C₃-C₇ cycloalkyl, monofluorocycloalkyl, polyfluorocycloalkyl or cycloalkenyl; phenyl, thiophenyl, pyridyl, pyrrolyl, furanyl, imidazolyl or indolyl; or —COOR₆, —COR₆, —CONHR₆, —CN, —OH or —OR₆; wherein each m is independently an integer from 0 to 3; wherein o is an integer from 1 to 3; wherein each n is independently an integer from 0 to 5; wherein each R₆ is independently H; straight chained or branched C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl; or C₃-C₇ cycloalkyl, monofluorocycloalkyl, polyfluorocycloalkyl or cycloalkenyl; wherein R₇ is phenyl, pyridyl, thiophenyl, furanyl, pyrazinyl, pyrrolyl, naphthyl, indolyl, imidazolyl, benzfurazanyl, benzfuranyl or benzimidazolyl; or C₁-C₇ alkyl, monofluoroalkyl or polyfluoroalkyl, C₂-C₇ alkenyl or alkynyl, wherein the alkyl, monofluoroalkyl, polyfluoroalkyl, alkenyl or alkynyl is substituted with phenyl, pyridyl, thiophenyl, furanyl, pyrazinyl, pyrrolyl, naphthyl, indolyl, imidazolyl, benzfurazanyl, benzfuranyl or benzimidazolyl; wherein each of Y₁, Y₂ and Y₃ is as defined above; wherein X is as defined above; wherein Z is C₂ alkenyl or alkynyl, CH₂, O, CONR₆, S, SO, SO₂ or NR₆; and wherein each D is independently CH₂, O, S, NR₆, CO or CS; or a pharmaceutically acceptable salt thereof.
 4. A method of treating a subject suffering from benign prostatic hyperplasia which comprises administering to the subject an amount effective to treat benign prostatic hyperplasia of the compound of claim 1 having the structure:


5. A method of treating a subject suffering from benign prostatic hyperplasia which comprises administering to the subject an amount effective to treat benign prostatic hyperplasia of the compound of claim 1 having the structure:


6. A method of treating a subject suffering from benign prostatic hyperplasia which comprises administering to the subject an amount effective to treat benign prostatic hyperplasia of the compound of claim 1 having the structure:


7. A method of treating a subject suffering from benign prostatic hyperplasia which comprises administering to the subject an amount effective to treat benign prostatic hyperplasia of the compound of claim 1 having the structure:


8. A method of treating a subject suffering from benign prostatic hyperplasia which comprises administering to the subject an amount of the compound of claims 1 in combination with a 5 alpha-reductase inhibitor effective to treat benign prostatic hyperplasia.
 9. The method of claim 8, wherein the 5-alpha reductase inhibitor is finasteride.
 10. A method of treating a subject suffering from benign prostatic hyperplasia which comprises administering to the subject an amount of the compound of claims 4, 5, 6, or 7 in combination with a 5 alpha-reductase inhibitor effective to treat benign prostatic hyperplasia.
 11. The method of claim 10, wherein the 5-alpha reductase inhibitor is finasteride. 